1. a mushroom-shaped valve that rises perpendicularly from its seat; commonly used in internal-combustion engines; [syn: poppet, poppet valve]
WordNet (r) 3.0 (2006):
poppet valve
n 1: a mushroom-shaped valve that rises perpendicularly from its
seat; commonly used in internal-combustion engines [syn:
poppet, poppet valve]