chassis
/ˈʃæsɪ/noun
(复同单/-sɪz/ )
1- the base frame of a motor vehicle, carriage, or other wheeled conveyance（机动车、马车或其他有轮运输工具的）底盘。
1.1
- the outer structural framework of a piece of audio, radio, or computer equipment（音响器材、收音设备或电脑的）机座; 机壳。
词源
early 20th cent.: from French chassis 'frame'， based on Latin capsa 'box' （see CASE2）.