assuage
/əˈsweɪdʒ/
transitive verb
Make (an unpleasant feeling) less intense.
the letter assuaged the fears of most members
relieve,ease,alleviate,soothe,mitigate,dampen,allay,calm,palliate,abate,lull,temper,suppress,smother,stifle,subdue,tranquillize,mollify,moderate,modify,tone down,attenuate,dilute,lessen,diminish,decrease,reduce,lower