Definition of "zonked"

zoegirl: yeah, but don’t say anything to my mom about it. (not that u would.) hey, i’ve gotta go to bed. i’m zonked.

2004, Lauren Myracle, ttyl, New York, NY: Amulet Books, page 57

The Pranksters had just held an Acid Test at the Fillmore Auditorium, a big ballroom in the middle of one of San Francisco's big Negro slums, the Fillmore district. It was a wild night. Hundreds of heads and bohos from all over the Bay area turned out, zonked to the eyeballs.

1968, Tom Wolfe, The Electric Kool-Aid Acid Test, Bantam, published 1997, page 225

[…] swingers in the audience were getting zonked on beer and fresh sea breezes and sound […]

1974 July, New York Magazine, volume 7, number 27

[…] playing eight-ball while zonked, chugging beer with locals […]

2004, Ed Sanders, Tales of beatnik glory