September is Etymology Month (13)

МАТЬ [mat'] 'mother'. 11th century, from CSl. *mati, gen. *matere, IE *mate/*mater-, id., based on onomatopoeic *ma, cf. Skr. matri, id., Gk. meter, id., Lat. mater, id. Loss of -r- is characteristic of Balto-Slav., cf. Lith. motina, id., Latv. mate, id. Cognates include мачеха 'step-mother' (with pejorative suffix -еха, cf. дурёха 'stupid woman').