Green’s Dictionary of Slang

dip n.6

[SE dip(somaniac)]

(US) a drunkard.

[US]Nebraska State Jrnl (Lincoln, NE) 14 June 9/4: Some of these dips — I believe they’re called dipsomaniacs by the people with the whiskers and the gold-topped prescription pencils — are queer bugs to study.
[US]Lincoln Daily News 5 Feb. in DN IV:ii 124: They (the sheriff and the inspector) wound up at the present East Side ball where there were a few dips present.
[US]Wentworth & Flexner DAS.