Green’s Dictionary of Slang

(orig. US) a filthy, disgusting, worthless person.

1934		B. Appel Brain Guy 138: None of the leaders were there, only a dozen or so of the crumbums and chisellers.
1944		E. Wilson 3 Oct. [synd. col.] [Toots] Shor, the plump ex-bouncer, famous for calling customers ‘crumbums’ .
1946		H.A. Smith Rhubarb 137: ‘That crumb bum!’ he said. ‘Him manager!’.
1951		J.D. Salinger Catcher in the Rye (1958) 103: So long, crumb-bum.
1958		H. Ellison Web of the City (1983) 52: His old man . . . That crumbum wouldn’t have to worry.
1959		A. Zugsmith Beat Generation 130: All he needed was the crumb-bum’s unquestioning subjection.
1965		(con. 1950s) Carmichael & Longstreet Sometimes I Wonder 301: The poetry-and-jazz crumbuns around here, they’re from Weirdsville if you ask me.
1985–6		J. Stahl ‘Finnegan’s Waikiki’ in Love Without (2007) 141: All I got from that crumb bum was a Purple Heart he didn’t even earn.
1989		H. Rawson Dict. of Invective (1991) 5: The use of alliteration and rhyme, as in boob tube, claptrap, crumb bum, flim-flam, gobbledygook, goo-goo, rinky-dink, ticky-tacky, and wishy-washy.
2002		Entertainment Weekly 🌐 Even despite ‘Save the Stripper!’ backing from David Letterman on ‘Late Show,’ even despite the argument that without her, ‘BB’ will be boring [...], folks voted to banish the crumbum.
2020		poster shown on Twitter 8 Nov. 🌐 trump is a crumb bum.