perineum (n.)youdaoicibaDictYouDict[perineum 词源字典]
"region of the body between the anus and the genital organs" (jocularly called a taint), early 15c., from Medieval Latin perinaeon, Late Latin perineum, from Greek perinaion, perinaios, from peri- "near" (see peri-) + inan "to carry off by evacuation," of unknown origin.[perineum etymology, perineum origin, 英语词源]