Entry 1 sense Webster, 1913 Spastic /spăs'-tĭk/ · Spas·tic · IPA /ˈspæstɪk/ 01 a. Of or pertaining to spasm; spasmodic; especially, pertaining to tonic spasm; tetanic. 1. Of or pertaining to spasm; spasmodic; especially, pertaining to tonic spasm; tetanic.(Med.)