Green’s Dictionary of Slang

break up v.

1. (US) to make someone very upset, to make someone ill with tension, to cause someone to cry.

[US]Bismarck (ND) Trib. 26 Jan. 8/1: The minister preached how vulgar it was to use slang [...] Just the minute I caught on to his racket, it broke me all up.
[US]E. Townsend Chimmie Fadden Explains 7: Say, honest, dat broke me all up.
[Aus]Bulletin (Sydney) 9 Aug. 17/2: This bard, who sits a-watching Nell, / With fingers white and slim, / Owns up that, as she breaks each shell, / She also ‘breaks up’ him; / And could devoutly drop upon / Submissive, bended knees.
[UK]Gem 16 Mar. 5: It broke my governor up.
[UK]Wodehouse ‘Wilton’s Holiday’ Man with Two Left Feet 42: He told me the whole thing so simply and frankly that it broke me all up.
[UK]E. Raymond Tell England (1965) 297: The boyish words broke me up. My brows contracted in pain. My eyes burned.
[UK]P. Cheyney Dames Don’t Care (1960) 126: I said it was pretty tough for me being sick to think she was running around with a guy who had swindled me. Well, that broke her up. I reckon she was sorry.
[Ire]B. Behan Quare Fellow (1960) Act II: It’ll break that young screw up.
[US]Mad mag. June 49: Man, I broke up at this crudest bird who wailed like some Zen Buddhist.
[US]E. De Roo Big Rumble 109: Next time I’ll break you both up, you fight in my store.
[Aus] in K. Gilbert Living Black 142: Well, it broke me up.
[NZ]McGill Dict. of Kiwi Sl. 21/1: break up demonstrate great amusement or, contrarily, upset.
[UK]N. Cohn Yes We have No 209: My ex-girlfriend has another man now, and that breaks me up.
[NZ]McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. (orig. US, also break it up) to cause someone to laugh or applaud heartily; to applaud heartily.

[US]‘Bill Nye’ Bill Nye and Boomerang 96: When I read this little thing [...] it broke me all up.
[US]C. Ryan ‘From “Quoz” to “Razzberries”’ in AS II:2 91: It is reported that a judge once used it inadvertently, and well nigh broke up the court.
[US]Cab Calloway New Hepsters Dict. in Calloway (1976) 253: break it up (v.): to win applause, to stop the show.
[US]W.R. Burnett Little Men, Big World 39: It must be something pretty funny to break up a tired broad like Lola.
[US]Billie Holiday Lady Sings the Blues (1975) 40: Then the house broke up. There’s nothing like an audience at the Apollo.
[US]H. Selby Jr Last Exit to Brooklyn (1966) 63: Roberta really broke us up.
[US]S. King Stand (1990) 151: This never failed to break Poke up. He brayed laughter.
[US]S. King Different Seasons (1995) 196: On the TV, Buddy Hackett had just broken everybody up.

3. (US) to act hysterically, to act irrationally.

[Aus]Bulletin (Sydney) 6 Jan. 12/3: Juvenile Melbourne was ‘breaking up,’ and showing off for many weary days before Plum-puddingness.
[Aus]K. Tennant Battlers 310: Poor old bugger’s breaking up fast.
[US]T. Wolfe Kandy-Kolored Tangerine-Flake Streamline Baby (1966) 24: I’m breaking up, and I don’t even know what’s happening to me.
[US]Bentley & Corbett Prison Sl. 93: Nut Up To completely lose control of oneself. […] (Archaic: blow one’s roof, break up).

4. (also break) to collapse in laughter.

‘Mark Twain’ in North Amer. Rev. Jan. 61: Well, humour is the great thing, the saving thing, [...] so, when M. Bourget said that bright thing about our grandfathers, I broke all up.
[US]Mad mag. Sept. 46: All the hipsters always break up when I make the scene. They keep laughing at me.
[US](con. 1940s) E. Thompson Tattoo (1977) He knew Glenn and Bucky were breaking up.
[US]R. Price Ladies’ Man (1985) 45: Jerry and Maurice broke up. Al basked in their laughter.
[US](con. 1982–6) T. Williams Cocaine Kids (1990) 100: Everybody in the joint broke. It was funny as shit.
[NZ]McGill Reed Dict. of N.Z. Sl.