null vs Fanny Adams

null and Fanny Adams both are nouns.

Word	Noun	Adjective	Verb	Adverb
null	Yes	Yes	No	No
Fanny Adams	Yes	No	No	No

As nouns, Fanny Adams is a hyponym of null; that is, Fanny Adams is a word with a more specific, narrower meaning than null:

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

Other hyponyms of null include nihil, bugger all, fuck all, sweet Fanny Adams.

null (noun)	Fanny Adams (noun)
a quantity of no importance; thing (object:), singular, negative pronoun; pronoun, thing, singular; quantifier: negative existential	nautical term for tinned meat
	little or nothing at all

null (adjective)	Fanny Adams (adjective)
lacking any legal or binding force