sweet Fanny Adams vs nix

sweet Fanny Adams and nix both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet Fanny Adams	Yes	No	No	No
nix	Yes	No	Yes	No

As nouns, nix is a hypernym of sweet Fanny Adams; that is, nix is a word with a broader meaning than sweet Fanny Adams:

sweet Fanny Adams: little or nothing at all
nix: a quantity of no importance; thing (object:), singular, negative pronoun; pronoun, thing, singular; quantifier: negative existential

Other hypernyms of sweet Fanny Adams include aught, cipher, cypher, goose egg, nada, naught, nil, nothing, null, zero, zilch, zip, zippo.

sweet Fanny Adams (noun)	nix (noun)
little or nothing at all	a quantity of no importance; thing (object:), singular, negative pronoun; pronoun, thing, singular; quantifier: negative existential

sweet Fanny Adams (verb)	nix (verb)
	command against