A shell suit is a type of athletic clothing that was popular in the 1980s and early 1990s. It typically features a brightly colored nylon or polyester outer layer and a thick, insulating interior lining. However, there are many different synonyms for the word "shell suit," depending on your location and the time period you are referring to. Some common alternatives include tracksuits, warm-up suits, jogging suits, and even windbreakers. Regardless of what you call them, these comfortable and practical garments are an excellent choice for anyone who enjoys working out, playing sports, or simply staying warm during the colder months of the year.