brachyuran UK /ˌbɹæk.iˈjʊə.ɹən/US /ˌbɹæk.iˈju.ɹən/adjective 1noun 1forms 1 adjective1 •Of or pertaining to true crabs. noun1 •A crab of the true crabs. A member of the infraorder Brachyura. formsbrachyurans