\[AE]*ol"i*pile\, AEolipyle \[AE]*ol"i*pyle\, n. [L.
aeolipilae; Aeolus god of the winds + pila a ball, or Gr. ?
gate (i. e., doorway of [AE]olus); cf. F. ['e]olipyle.]
An apparatus consisting chiefly of a closed vessel (as a
globe or cylinder) with one or more projecting bent tubes,
through which steam is made to pass from the vessel, causing
it to revolve. [Written also {eolipile}.]
Note: Such an apparatus was first described by Hero of
      Alexandria about 200 years b. c. It has often been
      called the first steam engine.