debriefing deb·rie·fing UK/diːˈbɹiːfɪŋ/ US/dɪˈbrifɪŋ/ uncommon noun 1. report of a mission or task Related words Word family debrief Broader terms reportinterrogation WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.