Meaning : Become quiet or calm, especially after a state of agitation.
Example :
After the fight both men need to cool off..
It took a while after the baby was born for things to settle down again..
Synonyms : calm, calm down, cool it, cool off, settle down, simmer down
Chill out ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Hindi. Chill out ka matlab kya hota hai?