Meaning of THEIRS in English

THEIRS

■ possessive pronoun used to refer to something belonging to or associated with two or more people or things previously mentioned.

Origin

ME: from their + -s 3 .

Usage

There is no need for an apostrophe: the spelling is ~ not their's .

Concise Oxford English vocab.      Сжатый оксфордский словарь английского языка.