rainy day woman, n. — Green’s Dictionary of Slang

rainy day woman n.

[ety. unknown; popularized and poss. coined by Bob Dylan in the song ‘Rainy Day Women Nos. 12 and 35’ (1966)]

(drugs) marijuana.

1966		Bob Dylan [song title] Rainy Day Women Nos. 12 and 35.
1969		R.R. Lingeman Drugs from A to Z (1970) 219: rainy-day woman marijuana cigarette.
1971		E.E. Landy Underground Dict. (1972).
2001		ONDCP Street Terms 17: Rainy day woman — Marijuana.