Lewis & Short

rĕtentĭo, ōnis, f. [retineo], a keeping back, i. e.,

  1. 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. ἐποχή), Cic. Ac. 2, 18, 59, and 2, 24, 78.
  2. II. A keeping back, retaining (postclass.): dotis, Dig. 31, 1, 79; 5, 3, 19; 10, 1, 30: urinae, retention, Cael. Aur. Tard. 3, 8.
    1. B. Preservation, maintenance: societatis, Lact. 6, 10 fin.: veteris disciplinae, Tert. adv. Marc. 5, 3: delicti, i. e. not to forgive, id. ib. 4, 28.
      In plur., Vitr. 9, 4.