urination (n.)

c. 1300, from Old French orine, urine (12c.) and directly from Latin urina "urine," from PIE *ur- (source also of Greek ouron "urine"), variant of root *we-r- "water, liquid, milk" (source also of Sanskrit var "water," Avestan var "rain," Lithuanian jūrės "sea," Old English wær, Old Norse ver "sea," Old Norse ur "drizzling rain"), related to *eue-dh-r (see udder).

1590s, back-formation from urination or else from Medieval Latin urinatus, past participle of urinare, from urina (see urine). Related: Urinated; urinating.