The term 'washroom tub' refers to a BASIN, typically made of porcelain, that is used for washing hands and other body parts. It is usually found in bathrooms and is connected to a plumbing system. The crossword solution for this term is 'BASIN, ' which is a five-letter word. A BASIN is a bowl-shaped container that is used for holding water or other liquids. It is often used for washing hands and other body parts, and is commonly found in bathrooms.