"expelling or having the quality of expelling flatulence," early 15c., from Latin carminativus, from past participle stem of carminare "to card," from carmen, genitive carminis, "a card for wool or flax," which is related to carrere "to card" (see card (v.2).
A medical term from the old theory of humours. The object of carminatives is to expel wind, but the theory is that they dilute and relax the gross humours from whence the wind arises, combing them out like knots in wool. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]
As a noun from 1670s.
late 14c., purgatif, in medicine, "having the property of cleansing by expelling impure matter from the body," from Old French purgatif (14c.) and directly from Late Latin purgativus, from purgat-, past-participle stem of Latin purgare "to cleanse, purify" (see purge (v.)). The noun is attested from early 15c., "a medicine that evacuates the intestines" (Old English medical texts have clænsungdrenc).
c. 1400, expulsioun, in medicine, "act of expelling matter from the body," from Old French expulsion or directly from Latin expulsionem (nominative expulsio), noun of action from past-participle stem of expellere "drive out" (see expel). From late 15c. as "forcible ejection, compulsory dismissal, banishment" as from a school or club.
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.