See indefinite in Webster's New World College Dictionary
adjective
not definite; specif.,
having no exact limits or having no limits at all
not precise or clear in meaning; vague
not sharp or clear in outline; blurred; indistinct
not sure or positive; uncertain
Bot. of no fixed number, or too many to count: said of the stamens, etc. of certain flowers
Gram. not limiting or specifying; not referring to a specific or previously identified person, thing, etc.: “a” and “an” are indefinite articles; “any” is an indefinite pronoun