mussel/ˈmʌsəl/EtymologyFrom Middle English muscle (“mussel”), from Old English muscle, from Proto-West Germanic *muskulā, from Late Latin muscula, from Latin mūsculus (“mussel, muscle”, literally “little mouse”). Doublet of muscle.mussel means any of several groups of bivalve shellfish with elongated, asymmetrical shells.; A freshwater mussel, usually edible, of the order Unionida in subclass Palaeoheterodonta. Lexicurio rates it Rare gem — a strength score of 81 out of 100.mussel is pronounced /ˈmʌsəl/.nounAny of several groups of bivalve shellfish with elongated, asymmetrical shells.; A freshwater mussel, usually edible, of the order Unionida in subclass Palaeoheterodonta.Any of several groups of bivalve shellfish with elongated, asymmetrical shells.; A saltwater mussel, usually edible, of the order Mytilida in subclass Pteriomorphia.Any of several groups of bivalve shellfish with elongated, asymmetrical shells.; Any of certain other bivalves of somewhat similar appearance, such as the zebra mussel and quagga mussel of the family Dreissenidae in subclass Heterodonta.