chill out vs settle down

chill out and settle down both are verbs.

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

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

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

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

chill out (verb)	settle down (verb)
become quiet or calm, especially after a state of agitation	become settled or established and stable in one's residence or life style
	become quiet or calm, especially after a state of agitation
	settle into a position, usually on a surface or ground