kitty-cat vs puss

kitty-cat and puss both are nouns.

Word	Noun	Adjective	Verb	Adverb
kitty-cat	Yes	No	No	No
puss	Yes	No	No	No

As nouns, kitty-cat and puss are synonyms defined as:

Other synonyms of kitty-cat include kitty, pussy, pussycat.

kitty-cat (noun)	puss (noun)
informal terms referring to a domestic cat	informal terms referring to a domestic cat
	obscene terms for female genitals