An Etymological Dictionary of the German Language/Annotated/mein
mein, possessive pronoun, ‘my,’ from Middle High German and Old High German mîn; in the same form it is the common Teutonic possessive pronoun from the stem me- of the personal pronoun (mir, mich, thus even in Middle High German and Old High German). This stem me- (in Gothic mi-s, ‘to me,’ mi-k, ‘me,’ accusative) is according to Latin meus, mihi, Greek μέ, Sanscrit ma, common to the Aryan division. Further details belong to grammar.