gnome vs Murphy's Law

gnome and Murphy's Law both are nouns.

Word	Noun	Adjective	Verb	Adverb
gnome	Yes	No	No	No
Murphy's Law	Yes	No	No	No

As nouns, Murphy's Law is a hyponym of gnome; that is, Murphy's Law is a word with a more specific, narrower meaning than gnome:

gnome: a short pithy saying expressing a general truth
Murphy's Law: humorous axiom stating that anything that can go wrong will go wrong

Other hyponyms of gnome include Sod's Law.

gnome (noun)	Murphy's Law (noun)
a short pithy saying expressing a general truth	humorous axiom stating that anything that can go wrong will go wrong
a legendary creature resembling a tiny old man; lives in the depths of the earth and guards buried treasure