Green’s Dictionary of Slang

jab v.

1. [20C+] (drugs) to inject drugs; thus jabbing n.

2. [1960s+] (US campus) of a man, to have sexual intercourse.

In compounds

jab job (v.) [job n.2 (2)]

[1950s+] (drugs) to inject a drug.

jaboff (n.) (also jabpopp, jabpoppo) [pop n.1 (4a)]

[1930s–50s] (US prison) an injection of drugs; the sensation that follows it.