Answer: weakens

AnswerCrossword Clue
WEAKENSEnervates
WEAKENSLoses strength
WEAKENSUndermines
WEAKENSWaters down
WEAKENSSaps
WEAKENSEases off
weakensMake or become weaker in power, resolve, or physical strength
weakensWEAKEN, to make weak (lacking strength)