Green’s Dictionary of Slang

1. to grab, to get hold of.

1967

(con. 1920s) J. Thompson South of Heaven (1994) 4: See if you can stem a little heat.

2. to beg (from).

1924		‘Digit’ Confessions of a Twentieth Century Hobo 164: The crazy little idiot had stemmed the law! He marched us to the police-station and booked us on a charge of begging.
1933		Ersine Und. and Prison Sl.
1950		Goldin et al. DAUL 209/2: Stem, v. To beg; cadge; panhandle.
1966		M. Braly It’s Cold Out There (2005) 192: You’re too big and healthy to stem.
1968		L. Wolf Voices from the Love Generation 6: I was living on the beach and stemming people.
1991		(con. 1920s) O.D. Brooks Legs 116: Don’t you know it’s against the law to stem people on the street?