Learn how to say Mollusk correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word mollusc:
an invertebrate of a large phylum which includes snails, slugs, mussels, and octopuses. They have a soft unsegmented body and live in aquatic or damp habitats, and most kinds have an external calcareous shell.
Phylum Mollusca: several classes, in particular Gastropoda, Bivalvia, and Cephalopoda
late 18th century: from modern Latin mollusca, neuter plural of Latin molluscus, from mollis ‘soft’