1.
one of them; some one (of several); any one (of several)
An indefinite pronoun referring to an unspecified item from a group of three or more things.
Related Words
Related:
どこか (somewhere)
Related:
誰か (someone)
Related:
何か (something)
Related:
どちらか (one of two)
Compare:
いずれか (one or the other)
Related:
どっちか (either one)