| 1. belonging to them. theirtheir , pron. & a. [oe. thair, fr. icel. ?eirra, ?eira, of them, but properly gen. pl. of the definite article; akin to as. ?āra, ?&aemacr;ra, gen. pl. of the definite article, or fr. as. ?&aemacr;ra, influenced by the scandinavian use. see: that.] the possessive case of the personal pronoun they; as, their houses; their country.note: the possessive takes the form theirs when the noun to which it refers is not expressed, but implied or understood; as, our land is richest, but theirs is best cultivated. nothing but the name of zeal appears 'twixt our best actions and the worst of theirs |
