Green’s Dictionary of Slang

1. (US drugs) extremely intoxicated by a drug.

1998

Mos Def, Q-Tip & Tash ‘Body Rock’ on Lyricist Lounge – Volume One [album] Yo what you skied up or treed up?

2. (US campus) thrilled.

1980

Eble Campus Sl. Fall 7: treed – elated, opposite of depressed.