piggish vs piggy

piggish is not a noun while piggy is a noun.

Word	Noun	Adjective	Verb	Adverb
piggish	No	Yes	No	No
piggy	Yes	Yes	No	No

As adjectives, piggish and piggy are synonyms defined as:

Other synonyms of piggish include hoggish, porcine, swinish.

piggish (noun)	piggy (noun)
	a young pig

piggish (adjective)	piggy (adjective)
resembling swine; coarsely gluttonous or greedy	resembling swine; coarsely gluttonous or greedy