Green’s Dictionary of Slang

1. to collapse or to surrender, both under unbearable pressure; to cause to knock out.

1913–14		Van Loan ‘No Business’ in Taking the Count 159: Bang! bang! in the pantry, and Isidore will fold up like a wet towel.
1929		A.J. Barr Let Tomorrow Come 157: He’ll fold up like a whore’s bed.
1936		K. Mackenzie Living Rough 37: That Goo-goo sure folded up. His head bounced on the canvas.
1947		Illus. 15 Mar. 19: Farrar hasn’t folded up after all. He’s sprung back again.
1953		J. Thompson Criminal (1993) 15: He folded up like an accordion.
1959		W. Brown Teen-Age Mafia 21: He hoped the mark wouldn’t fold up at the first blow.
1966		P. Boyle At Night All Cats Are Grey 67: The silly bugger must have folded up after having a pumpship.
1970		L. Bangs in Psychotic Reactions (1988) 37: Most of your current ‘phenomena’ [...] would just fold up a stupefied loss.
1979		E. Torres After Hours 252: With all this heat, you’re gonna fold up.
1999		E. Bunker Mr Blue 216: He folded up en route to a score (‘I can’t do it, man. I just can’t do it’).

2. (drugs) to withdraw from drug use.

1938		D. Maurer ‘Argot of the Und. Narcotic Addict’ Pt 2 in AS XIII:3 184/2: To fold up. To stop taking narcotics.
1949		Monteleone Criminal Sl. (rev. edn).
1953		Anslinger & Tompkins Traffic In Narcotics 308: fold up. To take the drug cure.

3. to terminate an activity.

1939		Howsley Argot: Dict. of Und. Sl.
1946		J.E. Dadswell Hey, Sucker 30: A few will go broke on the road – ‘fold up’ as show people say – their equipment being scattered by creditors.
1948		D. Dodge Bullets For The Bridegroom (1953) 27: It’s usually slack about this time. The night-hawks are folding up, and the morning crowd comes in after breakfast.
1954		(con. 1940s) T.A.G. Hungerford Sowers of the Wind 127: That just about folded up the night.

4. to knock down, to defeat, thus fig, to turn against, to decry.

1955		R. Graziano Somebody Up There Likes Me (1956) 272: The last round I prayed and punched and got strength I don’t know where from [...] It was enough to fold up Charley Fusari.
1971		E. Wilson Show Business Nobody Knows 255: They [i.e the press] were planning to fold up on her. But s [i.e. Lauren Bacall] he wasn’t, and they didn’t.

5. (also fold out) to leave.

1960

G. Swarthout Where the Boys Are 203: The Mike Todd of Michigan State had folded out of town.

6. to shut down someone’s business or other activity.

1973		E. Bunker No Beast So Fierce 75: What happened to the bail bond business? I hear they folded you up?
1974		D. Ireland Burn 82: If I fold up you can work with the big men.