Green’s Dictionary of Slang

1. crazy, eccentric.

1899–1900		C.L. Cullen Tales of the Ex-Tanks 337: The gambling bug [...] is a buzzier proposition than either rum or dope.
1930		F. Brett Young Jim Redlake in DSUE (1984) n.p.: Ladylike poems and high-class music and scenery that sends you buzzy.
1982		S. King Different Seasons (1995) 497: My head was a trifle buzzy from my evening’s intake of alcohol. [...] But the feeling was not at all unpleasant, and I had no sense of an impending hangover.

2. tense, on edge.

2012

J. Fagan Panopticon (2013) 154: Something flies up from a field to my left and I shit myself. I’m still buzzy, hyper-aware.