perineum

Etymology

Borrowed from Late Latin perinaeum, from Ancient Greek περίναιον (perínaion, “space between the anus and scrotum”), from Ancient Greek περίνεος, περίνεοι (períneos, períneoi, “male genitals”), itself from earlier Ancient Greek περίς (perís, “penis”) through influence from Ancient Greek πηρίς (pērís, “scrotum”).

noun

1. (anatomy) The region between the human genitalia, especially the scrotum, and anus. The male perineum is between the scrotum and anus. The female perineum is between the vagina and anus.
   He was attacked with complete retention of urine, after a debauch, and six weeks afterwards an abscess formed in the perineum, which eventually burst, leaving a fistulous opening, through which the urine continued to be discharged to the period of his admission into the Hospital. 1827, Guy's Hospital: Case of Fistula in Perineo, Successfully Treated: The Lancet, volume 12, page 61
   The prostate is surrounded by venous plexi and the perineum has a rich blood supply. 2005, Brian J. Moran, “27: Using the perineal pressure applicator device”, in Adam P. Dicker, Gregory S. Merrick, Frank M. Waterman, Richard K. Valicenti, Leonar G. Gomella, editors, Basic and Advanced Techniques in Prostate Brachytherapy, page 251
   The perineum is diamond shaped and stretches from the pubic symphysis to the coccyx. 2011, Ian Lyons, Biomedical Science: Lecture Notes, page 371