Green’s Dictionary of Slang

1. (US black) filthy, dirty.

1945

C. Himes If He Hollers 149: [A]s low as a white whore in a Negro slum—a scrummy two-dollar whore.

2. (N.Z.) lice-ridden.

1988		(ref. to WWI) McGill Dict. of Kiwi Sl. 97/2: scrummy lousy; WWI soldiers.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].