dyad vs 2

dyad and 2 both are nouns.

Word	Noun	Adjective	Verb	Adverb
dyad	Yes	No	No	No
2	Yes	Yes	No	No

As nouns, 2 is a hypernym of dyad; that is, 2 is a word with a broader meaning than dyad:

dyad: two items of the same kind
2: the cardinal number that is the sum of one and one or a numeral representing this number

Other hypernyms of dyad include deuce, II, two.

dyad (noun)	2 (noun)
two items of the same kind	the cardinal number that is the sum of one and one or a numeral representing this number

dyad (adjective)	2 (adjective)
	being one more than one