Green’s Dictionary of Slang

(drugs) extremely intoxicated by a drug.

1989		(con. 1982–6) T. Williams Cocaine Kids (1990) 84: He says he gets so skied [high from cocaine], and that’s why he does these things.
1998		Mos Def, Q-Tip & Tash ‘Body Rock’ on Lyricist Lounge – Volume One [album] Yo what you skied up or treed up?
2001		ONDCP Street Terms 19: Skied — Under the influence of drugs.