Entry 1 sense Webster, 1913 Mater /mät'-ẽr/ · Ma·ter · IPA /ˈmeɪtɚ/ 01 n. See Alma mater, Dura mater, and Pia mater. 1. See Alma mater, Dura mater, and Pia mater. See: Alma mater, Dura mater, Pia mater