The term 'BIG COUCH' can be solved by the four-letter word 'SOFA'. A SOFA, or couch, is a piece of furniture used for seating two or more people. It is typically upholstered and often has armrests and a backrest. Sofas are usually found in living rooms, family rooms, dens, and bedrooms. They come in a variety of sizes, shapes, and styles, and can be used to create a comfortable and inviting atmosphere.