WordNet (r) 3.0 (2006):

get well
    v 1: improve in health; "He got well fast" [syn: get well,
         get over, bounce back] [ant: get worse, relapse]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "get well":
   bounce back, come around, come back, come round, come to,
   come up smiling, get about, get over, make a comeback, mend,
   pull round, pull through, rally, recover, recuperate, revive,
   survive, weather the storm