TRAN'QUILIZE, verb transitive To quiet; 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. Religion haunts the imagination of the sinner, instead of tranquilizing his heart.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI