Entry 3 senses · 2 variants Webster, 1913 Amnestic · Am·nes·tic · IPA /æmˈnɛs.tɪk/ a. n. 01 a. Causing loss of memory. 1. Causing loss of memory. 2. Of or pertaining to amnesia. 02 n. A drug causing loss of memory. 1. A drug causing loss of memory.