Synonyms for Subside:

n.

crater. come down, cave in, tumble, topple, collapse, fall down, give way, fall in. subside (noun)
lessen, settle, sink.

v.

change (verb)
lessen.
decrease (verb)
compress, lessen, curtail, recede, deflate, deplete, deduct, diminish, abbreviate, shrink, truncate, abate, concentrate, wane, erode, decrement, decrease, die down, shorten, compact, dwindle, lower, contract, drain, abridge.
die down; decrease (verb)
diminish, lower, recede, wane, let up, sink, dwindle, settle, abate, cave in, collapse, slacken.
motion (verb)
settle, sink.
recede (verb)
wane, study at wane.
rest (verb)
quiet, stand, still, mark time, pause, stagnate, vegetate, stay, becalm, calm, rest, sleep, settle, fix, settle down, tranquilize, slumber, wait.

Other synonyms:

bate. fall in, topple. fall down, slacken. remit. collapse, tumble. come down. shift. blow over
die down.
decrease
slack off, slacken.
recede
recede.

Usage examples for subside

  1. It was about four o'clock in the afternoon that the fever which had been very high all through the day, began to subside – The Lights and Shadows of Real Life by T.S. Arthur Edition: 10 Language: English
  2. With the casting off of the slough the phenomena of inflammation to a great extent subside the pain ceases, and the case under ordinary conditions commences to mend. – Diseases of the Horse's Foot by Harry Caulton Reeks