adj.
Pronunciation: ' th erz
Function: pronoun, singular or plural in construction
Date: 14th century
1 : that which belongs to them ― used without a following noun as a pronoun equivalent in meaning to the adjective their
2 : his or hers : HIS , HERS ― used with an indefinite third person singular antecedent <I will do my part if everybody else will do theirs >