1) Appease 2) Assuage 3) Conciliate 4) Gruntle 5) Hypnotise 6) Hypnotize 7) Lenify 8) Mollify 9) Pacify 10) Placate 11) Reassure 12) Tranquilize 13) Tranquillise 1) Calm 2) Calm down 3) Comfort 4) Console 5) Lull 6) Make calm or still 7) Quiet 8) Quieten 9) Solace 10) Soothe 11) Still 12) Tranquilize 13) Tranquillise 
• (v. t.) 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.
tranquillize (U.S.)