What does "aeolipyle" mean?

Aeolipyle: 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.