Green’s Dictionary of Slang

topi n.

also tops

[? the top of the peyote cactus]

(drugs)

1. peyote.

1969		R.R. Lingeman Drugs from A to Z (1970).
2001		ONDCP Street Terms 21: Tops — Peyote.

2. mescaline.

2001

ONDCP Street Terms 21: Topi — Mescaline.