mid-15c., from Latin praematurus "early ripe" (as fruit), "too early, untimely," from prae "before" (see pre-) + maturus "ripe, timely" (see mature (v.)). Related: Prematurely; prematurity; prematuration. Premature ejaculation is attested from 1848; Latin euphemism ejaculatio praecox dates to 1891 in English but was used earlier in German and appears to have been, at first at least, the psychologist's term for it.
premature pre·ma·ture (prē'mə-tyur', -tur', -chur')
Occurring or developing before the usual or expected time.
Born after a gestation period of less than the normal time, especially, in human infants, after a period of less than 37 weeks.