(n.) A contraction of amperometer or amperemeter.

PCV valve alternator ammeter atom smasher atomic accelerator atomic cannon bearings bonnet boot brake bucket seat bumper camshaft carburetor chassis choke clutch connecting rod convertible top cowl crank crankcase crankshaft cutout cylinder cylinder head dash dashboard differential distributor exhaust exhaust pipe fan fender flywheel gear gearbox gearshift generator headlight headrest hood horn ignition intake manifold muffler parking light particle accelerator piston power brakes power steering radiator rear-view mirror seat belt shock absorber spark plug speedometer springs starter steering wheel top transmission universal valve windscreen windshield