chill out vs calm down

chill out and calm down both are verbs.

Word	Noun	Adjective	Verb	Adverb
chill out	No	No	Yes	No
calm down	No	No	Yes	No

As verbs, chill out and calm down are synonyms defined as:

chill out and calm down: become quiet or calm, especially after a state of agitation

Other synonyms of chill out include calm, cool it, cool off, settle down, simmer down.

chill out (verb)	calm down (verb)
become quiet or calm, especially after a state of agitation	become quiet or less intensive
	make calm or still
	become quiet or calm, especially after a state of agitation