The crossword solution for the term 'Structure Opening' is INFRA, which is a five-letter word. INFRA is a Latin word meaning 'BELOW' or 'BENEATH'. It is commonly used in engineering and architecture to refer to the infrastructure of a building or structure, such as the foundation, walls, and other components that support the structure. An INFRA opening is an opening in the infrastructure of a structure, such as a window or door.