Green’s Dictionary of Slang

1. (US drugs) a narcotic injection.

1938		D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981) 99/1: bingo. See bing.
1949		Monteleone Criminal Sl. (rev. edn).
1953		Anslinger & Tompkins Traffic In Narcotics 303: bingo. An injection of a drug.
1959		J.E. Schmidt Narcotics Lingo and Lore.

2. (US black) a $1 bill.

1995

L. Stavsky et al. A2Z 7/2: bingo – a dollar bill: Come on, I only need one more bingo.