cool off is a verb meaning "become quiet or calm, especially after a state of agitation". It carries 3 recorded senses.
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.”
feel less enamoured of something or somebody
Definitions, synonyms and semantic relations for cool off come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.