A nightgown is a long, loose-fitting garment that is worn during sleep or other leisurely activities. It typically covers from the neck down to the feet and is made of lightweight fabrics such as cotton or silk. Nightgowns can be plain or decorated with patterns or lace, and they are available in various styles including short-sleeved, long-sleeved, sleeveless, and even strapless options. They provide comfort and warmth while allowing for easy movement during sleep.