The Collaborative International Dictionary
Tranquilize \Tran"quil*ize\, Tranquillize \Tran"quil*lize\, v. t. [imp. & p. p. Tranquilizedor Tranquilliized; p. pr. & vb. n. Tranquilizingor Tranquillizing.] [Cf. F. tranquilliser.] To render tranquil; to allay when agitated; to compose; to make calm and peaceful; as, to tranquilize a state disturbed by factions or civil commotions; to tranquilize the mind.
Syn: To quiet; compose; still; soothe; appease; calm; pacify.
Tranquilizing \Tran"quil*i`zing\, Tranquillizing
\Tran"quil*li`zing\, a.
Making tranquil; calming. `` The tranquilizing power of
time.''
--Wordsworth. -- Tran"quil*i`zing*ly or
Tran"quil*li`zing*ly, adv.
Wiktionary
vb. (present participle of tranquillize English) (alternative spelling of tranquilizing English)