skate, v.² — Green’s Dictionary of Slang

skate v.²

[skating should be on ice but this antedates ice n.¹ (5); thus ? ref. to snow n.¹ (2)]

(US drugs) to use morphine or cocaine.

c.1925		R. McAlmon Miss Knight (1963) 50: If she was skatin’ – you know, coke, I mean, and they sells it in this burg by the bowlfuls.
1953		Anslinger & Tompkins Traffic In Narcotics 314: skate. To use morphine.