Dictionary:

denumerable

  (dĭ-nū'mər-ə-bəl, -nyū'-)

Capable of being put into one-to-one correspondence with the positive integers; countable.

[From denumerate, to count, from Late Latin dēnumerāre, dēnumerāt-, alteration of Latin dīnumerāre : dī-, dis-, dis- + numerāre, to number; see numerate.]

The adjective has one meaning:

Meaning #1: that can be counted
  Synonyms: countable, enumerable, numerable