vulgar (adj.) Look up vulgar at Dictionary.com
late 14c., "common, ordinary," from Latin vulgaris, volgaris "of or pertaining to the common people, common, vulgar, low, mean," from vulgus "the common people, multitude, crowd, throng," perhaps from a PIE root *wel- "to crowd, throng" (cognates: Sanskrit vargah "division, group," Greek eilein "to press, throng," Middle Breton gwal'ch "abundance," Welsh gwala "sufficiency, enough") [not in Watkins]. Meaning "coarse, low, ill-bred" is first recorded 1640s, probably from earlier use (with reference to people) with meaning "belonging to the ordinary class" (1530). Related: Vulgarly.