Entry 2 senses · 2 variants Webster, 1913 Dement /dəm-ĕnt'/ · De·ment · IPA /dəˈmɛnt/ v. t. a. 01 v. t. To deprive of reason; to make mad. 1. To deprive of reason; to make mad.[R.] 02 a. Demented; dementate. 1. Demented; dementate.[R.]