late 14c., "act of expelling contents of the stomach through the mouth," from Anglo-French vomit, Old French vomite, from Latin vomitus, from vomitare "to vomit often," frequentative of vomere "to puke, spew forth, discharge," from PIE root *weme- "to spit, vomit" (source also of Greek emein "to vomit," emetikos "provoking sickness;" Sanskrit vamati "he vomits;" Avestan vam- "to spit;" Lithuanian vemti "to vomit," Old Norse væma "seasickness"). In reference to the matter so ejected, it is attested from late 14c.
1650s (n.) "medicine that induces vomiting;" 1660s (adj.) "inducing vomiting;" from French émétique (16c.), from Latin emeticus, from Greek emetikos "causing vomiting," from emesis "vomiting," from emein "to vomit," from PIE *weme- "to spit, vomit" (see vomit (v.)).
