A joist is a structural SUPPORT element used in construction. It is typically made of wood, metal, or concrete and is used to SUPPORT the weight of a structure. The term 'joist' can also refer to the crossword solutions SUPPORT (7 letters) and BEAM (4 letters). SUPPORT is a structural element that provides stability and strength to a structure, while BEAM is a long, straight, rigid piece of material used to SUPPORT a structure. Together, these two elements form a joist, which is an essential part of any building's foundation.