chassis

Concise Oxford English Dictionary © 2008 Oxford University Press:
chassis /ˈʃasi/

▶noun (pl. same /-sɪz/)

• 1 the base frame of a motor vehicle, carriage, or other wheeled conveyance.

• 2 the outer structural framework of a piece of audio, radio, or computer equipment.

– origin early 20th cent.: from Fr. châssis ‘frame’, based on L. capsa (see case2).