Answer: dampens

AnswerCrossword Clue
DAMPENSDulls
DAMPENSMuffles
DAMPENSSuppresses
DAMPENSDepresses.
DAMPENSThrows cold water on
dampensto deaden
dampensmoist
dampensDAMPEN, to moisten (to make moist (slightly wet))
dampensto discourage
dampensmoisture
dampensto moisten