cool off in WordNet English dictionary

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."
   calm  calm down  cool off  chill out  simmer down  settle down  cool it 
   
2. lose intensity
   "His enthusiasm cooled considerably"
   cool  cool off  cool down 
   
3. feel less enamoured of something or somebody
   cool off 
   

cool off in English Wiktionary