soothe
allay, alleviate, appease, assuage, calm, calm down, compose, ease, hush, lull, mitigate, mollify, pacify, quiet, relieve, settle, smooth down, soften, still, tranquillize
Antonyms
aggravate (informal) agitate, annoy, disquiet, disturb, exacerbate, excite, get on one's nerves (informal) hassle (informal) increase, inflame, irritate, rouse, stimulate, upset, vex, worry