Breathing aids are devices used to help people with breathing difficulties. GILLS (5 letters) are organs found in fish and some other aquatic animals that allow them to extract oxygen from the water. GILLS (4 letters) are also a type of breathing aid, usually made of fabric, which is worn over the nose and mouth to help filter air and provide extra oxygen. Inhalers (8 letters) are another type of breathing aid, which deliver medication directly into the lungs to help open up the airways.