deaden
verb
1 surgeons used ether to deaden the pain:
numb, stifle, dull, blunt, suppress;
alleviate, mitigate, moderate, weaken, diminish, reduce, decrease, lessen, palliate, abate, ease, soothe, relieve, assuage, subdue, take the edge off, get rid of, put an end to.
▷antonyms intensify.
deaden Oxford Dictionary of English