coquette vs chat up

coquette is a noun but chat up is not a noun.

Word	Noun	Adjective	Verb	Adverb
coquette	Yes	No	Yes	No
chat up	No	No	Yes	No

As verbs, coquette and chat up are synonyms defined as:

coquette and chat up: talk or behave amorously, without serious intentions

Other synonyms of coquette include butterfly, coquet, dally, flirt, mash, philander, romance.

coquette (noun)	chat up (noun)
a seductive woman who uses her sex appeal to exploit men

coquette (verb)	chat up (verb)
talk or behave amorously, without serious intentions	talk or behave amorously, without serious intentions
	talk to someone with the aim of persuading him