\De*mag"net*ize\, v. t. 1. To deprive of magnetic properties. See {Magnetize}. If the bar be rapidly magnetized and demagnetized. --Am. Cyc. 2. To free from mesmeric influence; to demesmerize. -- {De*mag`net*i*za"tion}, n. -- {De*mag"net*i`zer}, n.