violaceousPronunciation: /ˌvʌɪəˈleɪʃəs/Definition of violaceous adjective 1chiefly technical of a violet colour: the fruiting body is pink or violaceous 2 Botany relating to or denoting plants of the violet family (Violaceae). Origin: mid 17th century: from Latin violaceus (from viola 'violet') + -ousviolaceous in other Oxford dictionaries Definition of violaceous in the US English dictionary