Chassis

[Sarah]

A traversing base frame, or movable railway, along which thecarriage of a barbette or casemate gum moves backward and forward.[See Gun carriage.]

[Dave Paprocki]

Noun: The female backside. Rumpshaker. [Booty]. Moneymaker. Ass. Heinie. Rear-end.

Noun: A superior hindquarters, usually on a well-proportioned female.

[Jason Yan]

What made Irish [playwright] Sean OCasey famous with that [line]: see below -- presumably a misuse of the word [chaos].

[Jessica]

A persons (usually a female) body. Derived from the frame (chassis) of an automobile. Almost always a positive reference.

[Couch Potatoe]

Chassis, usable in any situation. There is no bad time to say chassis

[Zipporah Schumaker]

The base frame of a car, carriage, or other wheeled vehicle.