spas·mod·ic (sp?z-m?d??k)adj.1. Relating to, affected by, or having the character of a spasm; convulsive.2. Happening intermittently; fitful: spasmodic rifle fire.3. Given to sudden outbursts of energy or feeling; excitable.[New Latin spasm?dicus, from Greek spasm?d?s, from spasmos, spasm; see spasm.]spas·mod?i·cal·ly adv.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.