The crossword solution for the term ONE IN A BED is OYSTER. An OYSTER is a type of mollusk that lives in saltwater and freshwater habitats. Oysters are filter feeders, meaning they filter out particles from the water to feed on. They are also known for their pearls, which are formed when an irritant gets stuck inside the OYSTER's shell. Oysters are a popular seafood delicacy and are often served raw or cooked.