
a large board placed behind the bowler, beyond the boundary, used to provide contrast to the ball, thereby aiding the striker in seeing the ball when it is delivered. Typically coloured white to contrast a red ball, or black to contrast a white ball.
Found on
http://cricker.com/glossary/

a large board placed behind the bowler, beyond the boundary, used to provide contrast to the ball, thereby aiding the striker in seeing the ball when it is delivered. Typically coloured white to contrast a red ball, or black to contrast a white ball.[8]
Found on
http://en.wikipedia.org/wiki/Glossary_of_cricket_terms

White-painted board placed at the end of the ground behind the bowler in order to give the batsman a clear background against which to see the ball. Also target offered to bowler who is having difficulty locating the wicket.
Found on
http://www.wandererscricket.com/glossary.html
No exact match found.