cool off

(verb) become quiet or calm, especially after a state of agitation. Synonyms: calm, calm down, cool off, chill out, simmer down, settle down, cool it. Examples: "After the fight both men need to cool off.." "It took a while after the baby was born for things to settle down again.."

(verb) lose intensity. Synonyms: cool, cool off, cool down. Example: "His enthusiasm cooled considerably."

(verb) feel less enamoured of something or somebody. Synonyms: cool off.