chat up vs coquette

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

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

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

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

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

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

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