What is a bollusk?

Answer 1

i think you mean what is a Mollusk?

Mollusks are invertebrate animals belonging to the Phylum Mollusca. They have a soft body consisting of a visceral mass containing the internal organs, a muscular foot used for locomotion, and, in all mollusks except the bivalves, a head. In addition to the mouth, which may be located at the end of an elongated organ called a proboscis, the head often bears sensory tentacles and eyes. The mouth leads into a chamber known as the pharynx, which usually contains a radula, a flexible, ribbon-like structure consisting of numerous rows of minute teeth, used in obtaining food. In all mollusks the body wall surrounding the visceral mass is prolonged into a fleshy or sheet-like mantle, which usually contains glands that secrete the shell.