The term 'bottle cover' can be summarized by the crossword solution of CAP, which is a three letter word. A CAP is a type of lid or seal that is used to close off the opening of a bottle. It is typically made of plastic or metal and is designed to fit snugly over the top of the bottle. Caps are often used to keep beverages fresh and prevent spills. They are also used to store and transport liquids, such as water, soda, beer, and wine.