PrairialPronunciation: /ˈprɛːrɪəl, pʀɛʀjal/Definition of Prairial noun the ninth month of the French Republican calendar (1793–1805), originally running from 20 May to 18 June. Origin:French, from prairie 'meadow'Prairial in other Oxford dictionaries Definition of Prairial in the US English dictionary