Lewis Short
(adverb) : tranquillō, , v. tranquillus, I. b. and II. b.
Charlton T. Lewis, Charles Short, A Latin Dictionary
Lewis Short
(verb) : tranquillo, āvi, 1, tranquillus
* To make calm or still, to calm, still.
* Lit. (very rare; syn. sereno): mare tranquillatur oleo,Plin. 2, 103, 106, § 234.
* Transf.: vultum,i. e. to clear up, brighten,Plaut. Capt. 1, 2, 21.
* Trop., to calm, compose, tranquillize (class.): ut aut perturbentur animi aut tranquillentur,Cic. Top. 26, 98: animos,id. Fin. 1, 16, 50: tranquillatis rebus Romanis,Nep. Att. 4, 5: quid pure tranquillet, honos an dulce lucellum,Hor. Ep. 1, 18, 102.
Charlton T. Lewis, Charles Short, A Latin Dictionary