II vs snake eyes

II and snake eyes both are nouns.

Word	Noun	Adjective	Verb	Adverb
II	Yes	No	No	No
snake eyes	Yes	No	No	No

As nouns, snake eyes is a hyponym of II; that is, snake eyes is a word with a more specific, narrower meaning than II:

II: the cardinal number that is the sum of one and one or a numeral representing this number
snake eyes: expressions used when two dice are thrown and both come up showing one spot

Other hyponyms of II include craps, brace, couple, couplet, distich, duad, duet, duo, dyad, pair, span, twain, twosome, yoke.

II (noun)	snake eyes (noun)
the cardinal number that is the sum of one and one or a numeral representing this number	expressions used when two dice are thrown and both come up showing one spot