Green’s Dictionary of Slang

1. (drugs) an occasional injection of a narcotic by anyone who is not addicted.

1939		Detective Fiction Weekly 18 Mar. 59/1: If you should happen to hear anybody speaking of a suey-pow or a joy-pop or of gowing out the lemon bowl, [...] bring him right here .
1949		Monteleone Criminal Sl. (rev. edn) 135: joy prop [sic] An occasional shot of narcotic.
1953		W. Brown Monkey On My Back (1954) 162: He thought maybe one or two were, but others just took a ‘joy-pop’ now and then.
1969		Cressey & Ward Delinquency, Crime, and Social Process 822: One may try repeatedly to take a few ‘joy pops’ and believe that he is controlling his habit.
1971		R.D. Pharr S.R.O. (1998) 132: ‘I’ll just take one little joy-pop before I go out’.
1980		(con. 1940s–60s) H. Huncke ‘Detroit Redhead’ in Eve. Sun Turned Crimson (1998) 108: Eventually picking up steady with a cat who was a junky — beginning to take an occasional joypop herself.
1989		J. Morton Lowspeak.

2. in fig. use.

1995

D. O’Donovan Tarantula Woman 48: This was Roscoe’s daily treat, the climax of his existence, his little joypop.