Where does “perineum” come from?

Perineum comes from Latin perinaeum, from Ancient Greek περίνεος, built from περί meaning "around" and Proto-Indo-European per- and pr̥tós.

perineum (English): The region between the human genitalia and anus

Definitions

Step	Language	Word	Meaning
1	Latin	perinaeum	—
2	Latin	perinaeon	—
3	Ancient Greek	περίναιον	Alternative form of περίνεος
4	Ancient Greek	περί
5	Latin	cambium	A change; cambium
6	Gaulish	cambion	change
7	Proto-Celtic	kambos	curved; twisted, crooked
8	Proto-Indo-European	kamp-	to bend; crooked; crooked