Lewis Short
(adj.adv.) : tăcĭturnus, a, um, adj.1. tacitus
* Not talkative, of few words, quiet, still, taciturn, silent, noiseless (mostly poet., but cf. taciturnitas): quia tristem semper, quia taciturnum videbant, * Cic. Sest. 9, 21: silentia,Lucr. 4, 583; Ov. A. A. 2, 505; id. M. 8, 84: obstinatio,Nep. Att. 22: deserta loca et taciturna,Prop. 1, 18, 1: ripa,Hor. C. 3, 29, 24: tineas pasces (liber) taciturnus inertes, silent, i. e. unread, id. Ep. 1, 20, 12: Liris taciturnus amnis,id. C. 1, 31, 8: vestigia,Ov. F. 1, 426.—Comp.: (ingenium) statuā taciturnius,Hor. Ep. 2, 2, 83.—Sup.: Pa. Valetne ostium? Ph. Bellissimum hercle vidi et taciturnissimum, Plaut. Curc. 1, 1, 20.— No adv.
Charlton T. Lewis, Charles Short, A Latin Dictionary