Definitions
1.adjectiveCapable of being counted; having a quantity.
2.adjective(of a set) Finite or countably infinite; having a one-to-one correspondence (bijection) with a subset of the natural numbers.
3.adjective(of a set) Countably infinite; having a bijection with the natural numbers.
4.adjective(grammar, of a noun) Freely usable with the indefinite article and with numbers, and therefore having a plural form.