Something that indicates or reveals information; a sign.
Any of various devices that indicate or register information, especially:
A time clock.
Nautical One of the brightly colored lengths of yarn or ribbon attached to the shrouds, stays, or sails of a sailboat, serving to indicate wind direction relative to the boat's motion.
A row of strips hung above a railroad track to warn a passing train of low clearance ahead.
Sports A resonant metal strip, 24 or 30 inches (61 or 76 centimeters) high, across the bottom of the front wall of a racquets or squash court above which the ball must be hit.
The American Heritage® Dictionary of the English Language, Fourth Edition