WordNet (r) 3.0 (2006):

cool off
    v 1: become quiet or calm, especially after a state of
         agitation; "After the fight both men need to cool off.";
         "It took a while after the baby was born for things to
         settle down again." [syn: calm, calm down, cool off,
         chill out, simmer down, settle down, cool it]
    2: lose intensity; "His enthusiasm cooled considerably" [syn:
       cool, cool off, cool down]
    3: feel less enamoured of something or somebody

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "cool off":
   arrange, array, arrest, bridle, calm down, check, collect oneself,
   compose oneself, constrain, contain, control, cool, cool it, curb,
   curtail, decelerate, deploy, dispose, dompt, enjoin, form,
   get organized, govern, grade, guard, harmonize, hierarchize,
   hinder, hold, hold at bay, hold back, hold fast, hold in,
   hold in check, hold in leash, hold up, inhibit, keep, keep back,
   keep from, keep in, keep in check, keep under control, lay out,
   lay under restraint, line up, marshal, methodize, normalize, order,
   organize, pacify, prohibit, pull, pull in, quiet, rank, regularize,
   regulate, rein, rein in, relax, restrain, retard, retrench,
   routinize, set back, set up, simmer down, slow down, snub,
   sober down, standardize, straiten, structure, systematize,
   take it easy, tranquilize, unwind, withhold