catflap.org Online Dictionary Query

  Home run \Home" run`\, n. (Baseball)
     a complete circuit of the bases made by the batter without
     being put out and without an error on the play; also, the hit
     on which the batter makes such a circuit; a four-base hit.
  
     Note: Most home runs are made when the batter hits a fair
           ball out of the playing area on a fly, when the ball
           cannot be played by the defending team; if a batter
           circuits the bases while the ball is still inside the
           playing field, it is an inside-the-park home run.
           [PJC]