ProboscideaPronunciation: /ˌprɒbəˈsɪdɪə/Definition of Proboscidea noun Zoology an order of large mammals that comprises the elephants and their extinct relatives. They are distinguished by the possession of a trunk and tusks. Origin:modern Latin (plural), from proboscisProboscidea in other Oxford dictionaries Definition of Proboscidea in the US English dictionary