onderstel

Onderstel is a Dutch noun meaning the underlying structure that provides support for something else. It denotes the frame, base, or substructure on which a larger object is built or rests. The term is used in engineering, automotive contexts, architecture, sculpture, and sometimes in more abstract uses to refer to the foundation of a system or argument. Etymology: from onder ('under') and stel ('set, arrangement').

In vehicles and machinery, het onderstel refers to the chassis or underframe, including the frame, suspension, axles, and wheels. It is typically contrasted with the bovenstel, the body or upper structure that sits on the onderstel. Maintenance and design discussions distinguish changes to the onderstel (affecting handling, durability, weight) from changes to the bovenstel.

In architecture and sculpture, onderstel can describe the substructure or supporting base that bears loads, such as a pedestal or plinth, though fundering or ondergrond are also used terms depending on context. In civil engineering contexts, onderstel may refer to the skeletal support that transfers loads to foundations.

Figuratively, onderstel can mean the underlying basis or framework of a theory, plan, or argument—its premises or fundamental assumptions.

See also: fundering, ondergrond, chassis, subframe.