Green’s Dictionary of Slang

1. suffering from alcoholic hallucinations; crazy.

1896		F. Hutcheson Barkeep Stories 39: Snaky, see? T’ought he had de Brooklyn boys, sure. Chances are dey got him out in de Washingtonian home er somewheres right now.
1933		Ersine Und. and Prison Sl.
1977		J. Langone Life at the Bottom 192: He flipped again, and he got hold of some booze and some medicine, and he just went snaky.

2. of alcohol, likely to render one very drunk.

1902

‘Curlew’ ‘Boko’ in Bulletin Reciter 1880–1901 157: I started drinking at the shanty on the Flat / Where the o.p. grog is snaky.

3. drunk.

1918		W.J. Schira diary 9 Dec. 🌐 Haig threw a Champagne bottle at me in the mess hall this p.m. It just missed my head. He is snakey.
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 225: Well, by God, Ellsworth, you were snaky last night.