any marine or freshwater crustacean of the order Amphipoda, such as the sand hoppers, in which the body is laterally compressed: subclass Malacostraca
adjective
2.
of, relating to, or belonging to the Amphipoda
amphipod in American English
(ˈæmfəˌpɑd)
noun
any of an order (Amphipoda) of malacostracan crustaceans with a vertically thin body and one set of legs for jumping or walking and another set for swimming, as the sand hopper