continence (n.)

late 14c., "self-restraint, moderation," especially with regard to desires and passions, "moderation in sexual intercourse, chastity, restraint of the sexual passions within lawful bounds," from Old French continence (14c.) and directly from Latin continentia "a holding back, repression," abstract noun from continent-, present-participle stem of continere "to hold back, check," also "hold together, enclose," from assimilated form of com "with, together" (see con-) + tenere "to hold" (from PIE root *ten- "to stretch").

In reference to the body's eliminatory functions, from 1915. Related: Continency.