effeminate vs sissy

effeminate is not a noun while sissy is a noun.

Word	Noun	Adjective	Verb	Adverb
effeminate	No	Yes	No	No
sissy	Yes	Yes	No	No

As adjectives, effeminate and sissy are synonyms defined as:

Other synonyms of effeminate include cissy, emasculate, epicene, sissified, sissyish.

effeminate (noun)	sissy (noun)
	a timid man or boy considered childish or unassertive

effeminate (adjective)	sissy (adjective)
having unsuitable feminine qualities	having unsuitable feminine qualities