The term 'fit securely' can be summarized by two crossword solutions: MESH (4 letters) and SEAT (4 letters). MESH is a type of fabric or material made up of connected strands that form a net-like structure. It is often used to make clothing, bags, and other items. SEAT is a piece of furniture designed to provide support and comfort for a person sitting in it. It is usually made of wood, metal, or plastic and is often padded with cushions. Together, these two words describe the concept of fitting something securely, such as a SEAT into a MESH fabric.