I am inevitable, immeasurable, inexorable, monstrous,
("I am inevitable" is a quote uttered by Thanos in Avengers: Endgame before he is killed at the start of the film. His past self also said this right before he believes to have won again, but this resulted in his defeat. He ironically starts this battle by quoting this, bragging about his relentless and unmatchable nature.)
With bars weighing on you harder than your haunting guilty conscience!
(Oppenheimer is among those who are credited with being the "father of the atomic bomb", a role which later led to him feeling an enormous amount of guilt. Thanos says his raps will hit Oppenheimer harder than his guilty conscience did.)
I am Thanos, and I crush tracks like Tesseracts in my palm!
(The Tesseract, also called the Cube, was a crystalline cube-shaped containment vessel which Thanos crushed to obtain the Space Stone. Thanos gloats that he excels in rapping and crushes rap tracks just like the Tesseract.)
You're a pencil-pushing Terran who never learned to love his bomb!
(Pencil-pushing is a term which refers to document work, and a Terran is a sci-fi term for an inhabitant of the Earth. Thanos disregards Oppenheimer as a mere boring human who is no match against him whatsoever and makes a reference to the film about a nuclear conflict, Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, to joke about how Oppenheimer later deeply regretted his creation of the atomic bomb.)
Seems you started off a chemist, and on your world you were a prodigy.
(Oppenheimer majored in chemistry and was known as a genius in the subject.)
Well, that makes sense, 'cause your rhymes are only hot periodically!
(Thanos makes a pun on the periodic table, a table of chemical elements, to say that Oppenheimer's raps are only good from time to time.)
Man, I burned the Avengers down to embers, sent half your planet to be slaughtered,
(When Thanos obtained all six Infinity Stones, he snapped his fingers with the Infinity Gauntlet to turn half the universe, including many of the Avengers, to dust.)
And now I'm offing Oppenheimer like I did to my daughter!
(In order to obtain the Soul Stone, Thanos sacrificed his daughter, Gamora, by throwing her off the mountains of Vormir. He says he will do the same to Oppenheimer.)
Got a fist of gold when I'm rapping, six Infinity Gems what I'm packing!
(Thanos flaunts his power to Oppenheimer as he wields a golden Infinity Gauntlet holding the six Infinity Stones, which allows him to manipulate the universe with a snap of his fingers.)
Stick your tiny nuclear dick back into your pants, Dr. Manhattan!
(Doctor Manhattan is a nuclear physicist from Watchmen who turned into a god-like being, often appearing completely nude, after a radioactive particle test accident. He is also named after the Manhattan Project, a research and development project during World War II that produced the first nuclear weapons, which Oppenheimer was a key part of. Thanos tells Oppenheimer to mind his own business.)
Hadron smashing all your atoms, best not collide with me when I'm rhyming
(In particle physics, a hadron is a subatomic composite particle made of two or more quarks held together by the strong force in a similar way as molecules are held together by the electromagnetic force. Thanos tells Oppenheimer not to collide with him like when two atoms may collide and release a burst of energy. This is also likely a reference to the Large Hadron Collider in Switzerland, the world's largest particle accelerator device and a key component in modern particle physics studies.)
'Cause you break and bleed so easy, I think I'll call you Oppen-hymen!
(Thanos calls Oppenheimer weak and makes a pun on the hymen, a thin piece of mucosal tissue that surrounds or partially covers the external vaginal opening which breaks and may bleed when a woman first has sexual intercourse.)
It's impossible to top me, Oppy, you just don't have the stones!
(Thanos says Oppenheimer simply can't beat him because he doesn't have the balls, or isn't brave enough, also making a pun on the Infinity Stones.)
Apparently the only thing you're good at wrecking is a home,
(Thanos says Oppenheimer won't be able to wreck him, and instead is only capable of wrecking homes. "Homewrecker" is a word for someone who has an affair with a married partner.)
'Cause you slept with your friend's wife, right there in your friend's bed,
(Oppenheimer had made friends with fellow chemist, Linus Pauling, but their friendship ended after Pauling suspected Oppenheimer was getting close to his wife, Ava Helen Pauling, after Oppenheimer had visited her at their home while Pauling was at work and suggested to Ava that they have a romantic tryst in Mexico. Thanos suggests Oppenheimer slept with Ava at the Pauling residence as well.)
Then got another married girl pregnant. You should have gone for the head.
(Oppenheimer and Katherine Puening, a radical Berkeley student and former Communist Party member, also created a minor scandal by sleeping together after a party, later finding out she was pregnant. "You should've gone for the head" was a quote by Thanos after Thor failed to kill him in Avengers: Infinity War, resulting in Thanos wiping out half the universe. Head is also a slang term for a blowjob, a form of oral sex which Thanos says Oppenheimer should have participated in to ensure his lover never got pregnant to begin with.)
("You took everything from me" is a quote Scarlet Witch says to Thanos in Avengers: Endgame before she overpowers him. Oppenheimer says listening to Thanos rap has taken the last of his energy.)
After your raps, I am become deaf.
(This is a reference to the famous speech by Oppenheimer where he quotes a Hindu scripture, "Now I am become Death, the destroyer of worlds." Oppenheimer makes a pun on the quote to say Thanos' raps made him deaf because they were awful.)
You need an Iron, Man, for that wrinkly-ass skin
(Iron Man is a member of the Avengers in the Marvel universe and was the one that defeated Thanos in Avengers: Endgame. Oppenheimer makes a joke on his name to say that Thanos need to iron his skin to make it look smooth as it is so wrinkly.)
And that butt-butt-butt-butt-butt-butt chin! (Here we go now.)
(Some humans are born with a natural indentation called a cleft chin, which may look similar to a butt, hence a "butt chin"; however, Thanos has multiple cracks in his chin similar to multiple butts, in which Oppenheimer mocks by saying "butt" six times to count them.)
Where's your rhythm? I thought you had the Time Stone.
(The Time Stone is one of the six Infinity Stones obtained by Thanos, which allows him to control time. Oppenheimer says Thanos should have rhythm and be able to stay in time with the track if he has the Time Stone.)
Your punchlines sound like they came from RhymeZone.
(RhymeZone is a website commonly used in raps to find a list of words which rhyme with another word. Oppenheimer calls Thanos' raps simplistic and uncreative, as if they were simply pulled from a website rather than being thought up by Thanos himself.)
You might be something in the MCU,
(The MCU, or the Marvel Cinematic Universe, is the name given to the franchise of Marvel movies and the universe in which they take place, where Thanos is a major villain.)
But between us? Who's the worst MC? You!
(Oppenheimer makes a play on words to say that although Thanos may be a big part in the MCU, compared to him he is the worst MC, or master of ceremonies.)
Your dialogue's got too many breaks in the syllables.
(Thanos often speaks very slowly with many breaks in his speech.)
You talk so slow, Drax thinks you're invisible.
(This is a reference to a scene from Avengers: Infinity War where Drax the Destroyer thought he had mastered the skill of moving so slowly that he becomes invisible.)
I cause chain reactions when I'm lyrical
(A chain reaction is the self-sustaining fission reaction spread by neutrons which occurs in nuclear reactors and bombs. Oppenheimer compares his raps to nuclear bombs.)
'Cause I've got that fissile material!
(In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction. Oppenheimer builds on what he said before by claiming his "material", that is the lyrics he has to work with, are so good that they can chain together with ease just like a nuclear chain reaction.)
You were born to Eternals, but came out looking out so scary
(Thanos is a mutant member of the race of superhumans known as the Titanian Eternals. Oppenheimer makes fun of Thanos' ugly appearance.)
That your own mother tried to make you a Temporary.
(Thanos' mother was so horrified of his appearance at birth that she attempted to murder him right after he was born. This would have made Thanos a "Temporary" as opposed to an "Eternal".)
Meanwhile, I've mastered the atom more than any man alive.
(Oppenheimer says he is a genius in the subject of atomic physics.)
Now I'm here to split U like 2 and 3 from 5.
(Oppenheimer references the isotope uranium-235, an element symbolized as 235U used in the development of the atomic bombs in the Manhattan Project. He makes a play on words on the element, saying that he will split Thanos like the nucleus of the uranium-235 atom during a nuclear reaction. If you split that isotope, you first get two atoms (Krypton and Barium) and three neutrons. Five is also the result when two and three are added to each other.)
I'm a peaceful man, but I do what I must.
(Oppenheimer says he is a peaceful man at heart, although he will do devastating things if he needs to. This again refers to the fact that Oppenheimer was not a warlike man and came to deeply regret his part in inventing the atom bomb. This, of course, makes him very different from the evil Thanos.)
You had an evil plan, Thanos, and it left you in the dust!
(Thanos had a plan to wipe out half the universe to make it more balanced, and was able to succeed in Avengers: Infinity War, turning half of all living creatures to dust. At the end of Avengers: Endgame, the Avengers got their hands on the Infinity Gauntlet, and in turn, Thanos himself was turned to dust. Being left in the dust also means to be left behind.)
It must leave you enraged, when you compare our talents
(Oppenheimer says that Thanos will be angry and disappointed if he tries to compare himself to Oppenheimer.)
Because in this battle, there is no balance!
(This is a reference to Thanos' plan to make the universe "perfectly balanced". Oppenheimer says that when it comes to rapping, they are not equal.)
For a communist pariah, you come off as awfully cocky,
(A pariah is an outcast, and Oppenheimer had a history of pro-Communist associations. Thanos says Oppenheimer is too arrogant despite this background. This is also a possible rebuttal to Oppenheimer's claim that the battle isn't balanced, as his Communist beliefs should make him prefer a more equal battle.)
But I'll make you bend the knee in round two like Nagasaki!
(On August 6th, 1945, the U.S. dropped an atomic bomb on Hiroshima, Japan, wiping out 90 percent of the city and killing 80,000 people. Three days later, the U.S. killed 40,000 people in Nagasaki with another atomic bomb. After another three days, the Imperial Japanese government surrendered. Thanos says that his second verse will make Oppenheimer surrender like the atomic bombing of Nagasaki did to the Imperial Japanese government.)
I'm the box office topper, the Marvel showstopper!
(Avengers: Infinity War and Avengers: Endgame both broke numerous box office records, with Avengers: Endgame becoming the highest-grossing film of all time. Thanos' appearance in the films was a key event in the storyline of the MCU, and he was deemed one of the largest threats to the Avengers in the whole franchise.)
Got my name on this win like it's the Thanoscopter!
(The Thanoscopter is a yellow helicopter with the word THANOS displayed on its tail, piloted by Thanos in two issues of Marvel comics.)
You just got no answer, for Fortnite's dopest dancer!
(Thanos was featured as a character in the Infinity Gauntlet Limited Time Mode of the popular video game, Fortnite Battle Royale. During this time, videos of Thanos performing various Fortnite dances became a viral meme across the internet. He says Oppenheimer would have nothing more to say to him as an answer.)
I will Loki choke you out like my name was throat cancer!
("Lowkey" is a word typically used to describe a speaker's desires or emotions, namely those of discretion and secrecy. This is used as a pun with Loki, a villain featured in Marvel comics and the MCU who Thanos killed by choking during the opening scene of Avengers: Infinity War. In 1966, Oppenheimer was diagnosed with throat cancer caused by forty years of heavy smoking, which later lead to his death. Thanos says he will leave Oppenheimer choked like cancer did to his throat, brutally killing him like Loki.)
J. Robert Oppenheimer:
You wanna talk about Death? How 'bout the one that looked at you and swiped left?
(In the comics, Thanos wipes out half the universe as an attempt to impress Mistress Death, the cosmic entity based on the personification of death, who ultimately remains uninterested. This is a reference to the mobile dating app, Tinder, where users swipe left on other users if they are not interested in them.)
I'm the destroyer of worlds, you got your nuts handed to you by a Squirrel Girl!
(This is another reference to the famous quote, "Now I am become Death, the destroyer of worlds." Squirrel Girl is a Marvel comics superheroine who is portrayed as being inexplicably able to beat some of the most powerful people in the universe, including Thanos, despite her comparatively silly powers derived from squirrels - so much so that she managed to defeat the entirety of the Marvel universe in a comic titled The Unbeatable Squirrel Girl Beats Up the Marvel Universe. This is also a play on words, as squirrels are animals known to eat nuts, though to "get your nuts handed to you" also means to be defeated.)
We're in the Endgame now, Tinky Winky.
("We're in the endgame now" is a quote said by Doctor Strange in Avengers: Infinity War, which is the source of the title of the sequel film, Avengers: Endgame. Tinky Winky is a character from the children's television show, Teletubbies, who has purple skin and is taller than the other Teletubbies. Oppenheimer mocks Thanos' appearance by comparing him to a childish character.)
I'll finish this like Ant-Man: all up in your stinky!
(Prior to the release of Avengers: Endgame, many fans came up with a theory that became a meme where Ant-Man, a Marvel superhero whose power includes the ability to shrink and expand to different sizes, would defeat Thanos by crawling into his anal cavity and expanding, killing him as he bursts out.)
Anyone who believes that "Thanos did nothing wrong" crap
("Thanos Did Nothing Wrong" is a phrase used in memes and online discussion about the actions of Thanos in Avengers: Infinity War, specifically absolving him of any ethical violations which would result from his plan to wipe out half of all life in the universe. On Reddit, a community called /r/ThanosDidNothingWrong was created shortly before the release of Infinity War. Oppenheimer believes that this dedication to Thanos' methods is ridiculous and unwarranted.)
Has obviously never heard you rap! Oh snap.
(Oppenheimer jokes that people who believe that phrase clearly have not heard Thanos rapping, as that would prove he had done something wrong. "Oh snap" is a playful exclamation of surprise, though it is also a reference to how Thanos snapped his fingers after obtaining all six Infinity Stones, wiping out half the universe, and to how Iron Man defeated Thanos by getting the Infinity Stones and snapping his fingers to wipe out Thanos and his entire army.)
J. Robert Oppenheimer:
When you talk you can drop a trough between each syllable!
(This lyric is what developed into the lyric, "Your dialogue's got too many breaks in the syllables.", with thinking there are so big space between each part of Thanos' words from how slow he talks, an object as big as a trough (which are common in the rural southwest) can be placed between them.)