Wiktionary
n. (context baseball English) The outfield defensive player that stands to the left of the center fielder as viewed from home plate.
WordNet
n. the person who plays left field
Wikipedia
In baseball, a left fielder (LF) is an outfielder who plays defense in left field. Left field is the area of the outfield to the left of a person standing at home plate and facing towards the pitcher's mound. In the numbering system used to record defensive plays, the left fielder is assigned the number 7.
Usage examples of "left fielder".
She swung mightily at the first ball pitched to her and hit it over the left fielder's head.
Svornin took a calculated risk that it would snare his rocket like a left fielder going after a fly ball.
The hit was a long fly ball that sent the left fielder backpedaling.
Some of his blood had spewed onto the torso of the Yankees current hot left fielder.
The Sarennian left fielder reached forth an interminable tentacle and nabbed it as it came smoking along the ground.