yesca, n. — Green’s Dictionary of Slang

yesca n.

also llesca, yesco, yeska

[Sp. llesca, tinder, fuel; pron. ‘yesca’]

(US drugs) marijuana.

1949		Monteleone Criminal Sl. (rev. edn) 257: yessa [sic] Marihuana.
1952		Lannoy & Masterson ‘Teen-age Hophead Jargon’ AS XXVII:1 31: YESCA, n. Marijuana [LAPD].
1971		E.E. Landy Underground Dict. (1972).
1981		E. Bunker Little Boy Blue (1995) 213: Drink some white port, smoke some yeska.
1993		L. Rodríguez Always Running (1996) 45: Dudes who sold and took drugs, mainly downers and yesca.
2001		ONDCP Street Terms 14: Llesca — Marijuana. [Ibid.] 23: Yesca [...] Yesco — Marijuana.