late 14c., "act of expelling contents of the stomach through the mouth," from Latin vomitare "to vomit often," frequentative of vomere "spew forth, discharge," from PIE root *wem- "to spit, vomit" (cf. Greek emein "to vomit," emetikos "provoking sickness;" Sanskrit vamati "he vomits;" Avestan vam- "to spit;" Lithuanian vemiu "to vomit," Old Norse væma "seasickness"). In reference to the matter so ejected, it is attested from late 14c.