Incapable of being numbered or reckoned; not to be counted for multitude; numberless, countless… With singular noun; now only with host, multitude…

Unreckonable.

with n. plural. Unlimited or indefinitely great in number; innumerable, very many, ‘no end of’. Now archaic or rare.

Without number, too numerous to be counted; innumerable, numberless, countless. Now only poetical or rhetorical.

Innumerable. Also occasionally as adverb: innumerably, infinitely.

With plural nouns: In large numbers; numberless, countless.

Not capable of being reckoned.

Beyond count or reckoning; countless, innumerable. Obsolete. rare.

Modifying a singular noun, usually one with collective or abstract meaning: having or consisting of countless elements, aspects, phases, etc…

Countless, innumerable.

Innumerable; numerous; (occasionally, describing a mass noun) considerable, extensive, multifarious… In attributive use.

Modifying a plural noun: existing in huge numbers; countless, innumerable. Also occasionally in predicative use.

Used to represent the words (I) don't know how many as said in informal conversation, in cases where how many is adjectival in function…

Countless, innumerable; having innumerable aspects or features.