Green’s Dictionary of Slang

1. to infest with vermin.

1931		Gang World Jan. 14: The precinct was fumigated yesterday, an’ you ain’t gonna louse it up again [OED].
1943		J. Mitchell McSorley’s Wonderful Saloon (2001) 23: Nobody ever got loused up in the Venice.
1955		R.P. Hobson Nothing Too Good for Cowboy 15: I got loused up in that cabin once .
1960		J. Havoc Early Havoc 53: ‘I’m awfull sorry about the — well, the bugs.’ ‘Aw hell! [...] We get loused up at least once in every show’.
1968		Listener 9 May 601/2: I was occasionally loused-up myself, and people, rather than pass me, used to go on the other side of the road .

2. (US prison) to wash one’s clothes to remove lice.

1929

A.J. Barr Let Tomorrow Come 4: G’wan in there and louse up.

3. to tease.

1938

W. Winchell On Broadway 28 Nov. [synd. col.] Club 18, where the clowns ‘louse up’ anybody. The bigger the shot, the bigger the rib.

4. (orig. US, also louse) to make a mess of, to ruin, usu. deliberately; thus loused-up adj.

1940		J.H. O’Hara Pal Joey 11: Boy you certainly louse that up.
1948		(con. 1944) N. Mailer Naked and Dead 94: They only been in one week and already they’re lousin’ up the platoon.
1952		(con. 1920s) ‘Harry Grey’ Hoods (1953) 153: All the loused-up movie stories of hoodlums breaking away from the mob.
1953–54		Mad mag. Dec.–Jan. 7: Again you come in in der middle of der experiments? Again you louse me up?
1956		H. Whittington Forgive Me, Killer (2000) 47: You could have been a credit to the department [...] You really loused.
1964		Larner & Tefferteller Addict in the Street (1966) 196: That’s why I’m a louse. ‘Cause I keep lousing up my life one step after another.
1970		San Diego Sailor 7: I didn’t want to louse anything up for us.
1989		M. Amis London Fields 377: She wasn’t going to let him be the louser-up of her reality.
2003		T. Dorsey Stingray Shuffle 60: You louse up more good books by thowing bodies around.

5. to cause a person difficulties, to cause trouble for someone.

1946		E. Wilson Pikes Peek or Bust 69: To a lady chatterbox at the ringside he may say, ‘My dear, I may have to louse you up—if I’m not too late’.
1950		M. Spillane in Mike Hammer Coll. (2001) 376: Quit lousing me up, Mike. I want to find out what happened .
1952		B. Appel Plunder (2005) 222: He was the prize jerk to louse himself up with whiskey.
1958		E. Gilbert Vice Trap 115: The hospital thought I was one more kid who had loused up her parents.
1961		in J. Cannon Nobody Asked Me 141: In my neighborhood you only wanted a lawyer when you got pinched. But fighters get them to louse up a manager [HDAS].

6. to blunder, to fail.

1950		Goldin et al. DAUL.
1961		B. Crump Hang On a Minute, Mate (1963) 152: I sat there lousing up games of five hundred and wiping sweat and hair-oil on the sleeve of Uncle Wally’s coat.

7. to make a place or situation unpleasant or nasty.

1952

P. Larkin letter 1 Oct. in Thwaite Sel. Letters (1992) 190: The Lake District was quite pretty, but loused up with numerous freaks tricked out in the cast off clothes of the AEF.

8. to dirty.

1953

‘John Eagle’ Hoodlums (2021) 58: Use a rented car, always a rented one [...] Splatter up the plates, at least louse up a couple of numbers.

9. see louse (around) under louse v.