hoi polloi (n.)

1837, from Greek hoi polloi (plural) "the people," literally "the many" (plural of polys, from PIE root *pele- (1) "to fill"). Used in Greek by Dryden (1668) and Byron (1822), in both cases preceded by the, even though Greek hoi means "the," a mistake repeated often by subsequent writers who at least have the excuse of ignorance of Greek. Ho "the" is from PIE *so- "this, that" (nominative), cognate with English the and Latin sic. From the adjective agoraios "pertaining to the agora; frequenting the market" Greek had hoi agoraioi "loungers in the market, loafers, common, low men."