themself /ðɛmˈsɛlf/ pronoun2 •[with oneself] (nonstandard) The reflexive form of they, the third-person singular personal pronoun. The single person previously mentioned, as the object of a verb or following a preposition (also used for emphasis).Someone could hurt themself.Anyone who wants a car like mine can buy one themself. •(nonstandard) Synonym of themselves (the third-person plural). formsof they