piece of tail vs dirty word

piece of tail and dirty word both are nouns.

Word	Noun	Adjective	Verb	Adverb
piece of tail	Yes	No	No	No
dirty word	Yes	No	No	No

piece of tail (noun)	dirty word (noun)
slang for sexual intercourse	an offensive or indecent word or phrase
	a word that is considered to be unmentionable