a member of the baseball team that is in the field instead of at bat
"The shortstop quickly tagged out the runner trying to steal second base before the ball even hit the ground."
A player of the fielding side, whose task is to gather the ball after the batsman has hit it, to catch the batsman out, or to prevent him from scoring.
"The shortstop quickly scooped up the ground ball and threw it home to tag the runner before he could score."
A surname.
"My neighbor, Fielder, invited me over for dinner last night."