Robe- A long, loose piece of clothing worn especially on very formal occasions. Gown- A woman's dress, especially a long one worn on formal occasions. Both gowns and robes are long garments. Robes are loose garments such as bathrobes or the black robes that court judges wear. Gowns can be tight and fancy such as women's wedding gowns, girl's prom dresses, and what female celebrities wear at the Golden Globes. There are loose-fitting gowns such doctor's white gowns, graduation gowns, and your nightgowns.