curtsy vs curtsey

curtsy and curtsey both are nouns.

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

As nouns, curtsy and curtsey are synonyms defined as:

curtsy and curtsey: bending the knees; a gesture of respect made by women

As verbs, curtsy and curtsey are synonyms defined as:

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

curtsy (verb)	curtsey (verb)
make a curtsy; usually done only by girls and women; as a sign of respect	bend the knees in a gesture of respectful greeting
bend the knees in a gesture of respectful greeting