barback
noun
bar·back ˈbär-ˌbak 
variants or bar-back
ˈbär-ˌbak
plural barbacks or bar-backs
chiefly US
: a worker whose job is to assist a bartender (as by setting out glasses and restocking beverages)
Then he moved to New York, where he started out as a barback at House of Brews in Midtown Manhattan before moving behind the bar.
Coley Ward, Arizona Daily Star, 21 Feb. 2008
Coley Ward, Arizona Daily Star, 21 Feb. 2008
Word History
First Known Use
1974, in the meaning defined above