copulation (n.)youdaoicibaDictYouDict[copulation 词源字典]
late 14c., "coupling," from Middle French copulation "mating, copulation" (14c.), from Latin copulationem (nominative copulatio), noun of action from past participle stem of copulare (see copulate). Of the sex act from late 15c., and this became the main sense from 16c.[copulation etymology, copulation origin, 英语词源]