falsifying fal·si·fying US/ˈfɔlsʌˌfaɪɪŋ/ rare noun 1. the act of determining that something is false Synonymsfalsificationdisproofrefutation Related words Word family refutefalsify Broader terms determination WordNet 2.1 (Princeton University). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.