n.
Pronunciation: ˌ ma-l ə - ' käs-tri-k ə n
Function: noun
Etymology: ultimately from Greek malakostrakos soft-shelled, from malakos soft + ostrakon shell ― more at MOLLIFY , OYSTER
Date: 1835
: any of a large subclass (Malacostraca) of crustaceans having a thorax consisting of eight segments usually covered by a carapace and including the decapods and isopods
– malacostracan adjective