underbody

plural underbodies

1. The underparts of a bird or animal.
2. The underside of a vehicle.

   “There was somebody’s entire fender or underbody on the racetrack,” he said.

   2007 May 14, Viv Bernstein, “Engine Woes Fail to Slow Hendrick Team’s Streak”, in New York Times

   1 more example

   The rest were undergoing special underbody cleaning safety checks at TfW depots, after speculation that the cause of the incidents may have been a build-up of engine oil and combustible material such as fallen leaves and general detritus.

   2023 March 22, “Network News: Class 175s withdrawn for safety checks after fires”, in RAIL, number 979, page 13