The term 'basis or foundation' can be summed up with the crossword solution 'FOOTING' (7 letters). A FOOTING is a structural element of a building that provides support for the walls and other structures. It is typically made of concrete and is placed below the ground level to provide stability and strength. Footings are an essential part of any construction project, as they provide the necessary support for the structure and help to prevent it from shifting or sinking.