1570s, probably related to Old French gosillier "to go down the gullet; to vomit, chatter, talk," from gosier (13c.) "jaws, throat, gullet." Or imitative of the sound of drinking greedily. Related: Guzzled; guzzling. As a noun from 1590s.
A heavy drinker of alcohol: guzzlers atthe VFW
[fr French gosier, ''throat,'' or perhaps like that French word, echoically based on the sound of swallowing]