alice, n. — Green’s Dictionary of Slang

alice n.

[pron. of proper name resembles L.S. – i.e. LSD – but note autobiographical novel Go Ask Alice, about a 15-year-old’s drug habits, and Jefferson Airplane song ‘White Rabbit’ (1967), with its drug-orientated lyrics, esp. the line ‘Go ask Alice, when she’s ten feet tall’; both refs. go back to Lewis Carroll’s Alice’s Adventures in Wonderland (1866), which was seized on by the hippies for its supposed drug refs.]

(drugs) LSD.

1972		B. Rodgers Queens’ Vernacular.
1995–2002		Addictions & Life Org. (US) 🌐 Drug Related Street Terms/Slang: Alice – LSD or mushrooms.
2003		K. Cage Gayle 53/1: Alice n. the drug LSD (Is Alice coming to the Cha Cha Palace tonight?) [from the pronunciation in certain South African dialects of the first two letters in LSD].