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Webster 1913 Edition
AEolipyle
{ 
, Æ-ol′i-pile
,Æ-ol′i-pyle
}Noun.
 [L. 
aeolipilae
; Aeolus 
god of the winds + pila 
a ball, or Gr. [GREEK] gate (i. e., doorway of Æolus); cf. F. éolipyle
.] 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
.] ☞ Such an apparatus was first described by Hero of Alexandria about 200 years 
b. c. 
It has often been called the first steam engine.