Reténtio, ônis, f.g. Verbal. Cic.An holding: a retayning: a staying backe.
Lewis and Short: Latin dictionary
rĕtentĭo, ōnis, f. [retineo], a keeping back, i. e., I.A holding back, holding in: aurigae, Cic. Att. 13, 21, 3; 13, 25, 1.—Trop., a withholding: assensionis (as a transl. of the Gr. e)poxh/), Cic. Ac. 2, 18, 59, and 2, 24, 78.— II.A keeping back, retaining (postclass.): dotis, Dig. 31, 1, 79; 5, 3, 19; 10, 1, 30: urinae,