Pronunciation (UK) IPA (key): /ræ.ʃəˈnɑːl/ (US) IPA (key): /ræ.ʃəˈnæl/ Audio (UK)(file) Noun Singular rationale Plural rationales (countable) A rationale is an explanation or reasons given for an action. Related words rational irrational rationalize/rationalise rationalization/rationalisationWikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads