recognise vs curtsy

recognise is not a noun while curtsy is a noun.

Word	Noun	Adjective	Verb	Adverb
recognise	No	No	Yes	No
curtsy	Yes	No	Yes	No

As verbs, curtsy is a hyponym of recognise; that is, curtsy is a word with a more specific, narrower meaning than recognise:

recognise: express greetings upon meeting someone
curtsy: make a curtsy; usually done only by girls and women; as a sign of respect

Other hyponyms of recognise include shake hands, bob, salute, present, salute, salute, hail, herald, receive, welcome, say farewell, bid, wish.

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

recognise (verb)	curtsy (verb)
perceive to be the same	make a curtsy; usually done only by girls and women; as a sign of respect
be fully aware or cognizant of	bend the knees in a gesture of respectful greeting
accept (someone) to be what is claimed or accept his power and authority
express obligation, thanks, or gratitude for
express greetings upon meeting someone
detect with the senses
grant credentials to
show approval or appreciation of