Met, syllaba, ornatus causa ponitur, & aduerbium est: vt Egomet. I my selfe.
Lewis and Short: Latin dictionary
met, a pronominal suffix attached to substantive and (less freq.) adjective personal pronouns; Engl. self: egomet, mihimet, memet, nosmet, nobismet, tutemet, tibimet, vosmet, meamet; v. ego, tu, and meus.