Lewis & Short

rĕtĭcentĭa, ae, f. [reticeo],

  1. I. a keeping silent, silence (rare but good prose): quid taces? enicas me miserum tuā reticentiā, Plaut. Merc. 5, 2, 52; Pac. ap. Non. 1, 31 (Trag. Rel. p. 94 Rib.): posterorum, Cic. Phil. 14, 12, 33: a jurisconsultis etiam reticentiae poena est constituta (viz. as to a defect in a thing sold), id. Off. 3, 16, 65.
  2. II. In rhetor., = aposiopesis, a pause in the midst of a speech, Cic. de Or. 3, 53, 205; Quint. 9, 1, 31; 9, 2, 54; 57.