Green’s Dictionary of Slang

(US) very drunk or intoxicated.

1984		Algeo Stud Buds and Dorks 6: to be drunk [...] gonzoed [HDAS].
1988		Eble Campus Sl. Mar.
2008		M.S. Granda It Shined 106: To help finish out the last set of the night, I became Gonzoed. No one cared. Everyone danced.