Meaning of warning track

warn'ing track"

Pronunciation: [key]
— Baseball. Baseball.
  1. a strip, often consisting of a cinder or dirt track, bordering the outer edge of the outfield between the outfield turf and the stadium wall that alerts outfielders that the wall is near, esp. as they back up to catch a fly ball.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.