1. A large phylum of invertebrate animals that typically have a soft body, a muscular foot, and a hard shell; includes snails, clams, octopuses, and squid.
Usage: scientific/taxonomic term; also spelled Mollusca (capitalized) when referring to the phylum; singular: mollusk or mollusc; plural: mollusks, molluscs, or mollusca

Examples

• Mollusca is one of the largest phyla in the animal kingdom.
• Snails and clams are both members of the phylum Mollusca.
• The octopus belongs to the class Cephalopoda within Mollusca.
• Marine biologists study mollusca to understand ocean ecosystems.
• Mollusca includes over 85,000 known species of soft-bodied animals.
• The shells of many mollusca are prized by collectors.