malacostracan Zoology [ ˌmalə'kɒstrək(ə)n ]
■ noun a crustacean of the large class Malacostraca, which includes crabs, shrimps, and lobsters, distinguished by having compound eyes that are typically on stalks.
■ adjective relating to malacostracans.
Origin
from mod. L. Malacostraca , from malaco- + Gk ostrakon 'shell'.