noun
also ae·ol·i·pyle or eol·i·pile ēˈäləˌpīl
( -s )
Etymology: Latin & Greek; Latin aeolipila, by folk etymology (influence of Latin pila ball) from Greek aiolipylē, Aiolon pylē, from aioli- (from Aiolos, god of wind) or Aiolon (gen. of Aiolos ) + pylē gate — more at pylon
: an apparatus that was invented in the 2d century B.C. and is often called the first steam engine and that consisted essentially of a closed vessel (as a globe or cylinder) with one or more projecting bent tubes out of which steam is made to pass from the vessel, the action of the steam jets causing it to revolve