Green’s Dictionary of Slang

1. (drugs) a period when drugs are in very short supply or even non-existent.

1961		T. Taylor Baron’s Court All Change (2011) 55: ‘We’ll get eight quid an ounce easy while this drought is on’.
1966		Current Sl. I:3 2/2: Drought, n. A time when the authorities make it difficult for addicts to obtain drugs.
1974		V.E. Smith Jones Men 166: It’s a drought or something. Ain’t nothin’ happenin’.
1994		P. Baker Blood Posse 280: I don’t want the drought to reach me and can’t get any ganga.
1997		L. Davies Candy 12: There’s a drought. Or you could say a flash flood. A flash flood of no heroin.
2010		K. Richards Life 406: When there was a heroin drought it was a bit rough.
2015		67 ‘Dead Up’ 🎵 Walk around with 5 zeds in my pouch / [...] / I smoke 1 cos it’s drought.

2. (orig. US campus) a period without sex or even dates.

1989

P. Munro Sl. U. 30: Steve hasn’t had a date in months — he’s in a serious drought.