Wiktionary
cool off
vb. 1 (context intransitive English) To decrease in temperature, activity, or temper. 2 (context transitive English) To cause to decrease in temperature, activity or temper.
WordNet
cool off
v. 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, chill out, simmer down, settle down, cool it]
lose intensity; "His enthusiasm cooled considerably" [syn: cool, cool down]
feel less enamoured of something or somebody