The Collaborative International Dictionary of English v.0.48:

Ejector \E*ject"or\, n.
   1. One who, or that which, ejects or dispossesses.
      [1913 Webster]

   2. (Mech.) A jet jump for lifting water or withdrawing air
      from a space.
      [1913 Webster]

   3. That part of the mechanism of a breech-loading firearm
      which ejects the empty shell.
      [Webster 1913 Suppl.]

   Ejector condenser (Steam Engine), a condenser in which the
      vacuum is maintained by a jet pump.
      [1913 Webster]