bow down vs curtsy

bow down is not a noun while curtsy is a noun.

Word	Noun	Adjective	Verb	Adverb
bow down	No	No	Yes	No
curtsy	Yes	No	Yes	No

bow down (noun)	curtsy (noun)
	bending the knees; a gesture of respect made by women

bow down (verb)	curtsy (verb)
bend one's knee or body, or lower one's head	make a curtsy; usually done only by girls and women; as a sign of respect
get into a prostrate position, as in submission	bend the knees in a gesture of respectful greeting