in·suf·fla·tion (?n?s?-fl??sh?n)n.1. The act or an instance of insufflating.2. Ecclesiastical A ritual act of breathing on baptismal water or on the one being baptized.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.