mid-on:
(plural: ‘mid-ons‘)
(in cricket sport) a player placed in a position near the bowling side (near the bowler), but on the opposite side of ‘mid-off’, on the field during the game,
The full form of ‘mid on’, in cricket, is ‘middle wicket on’.
In cricket mid-off, short-mid-off and mid-on are very important when the bowler is a medium-pacer. As they are placed opposite the batsman, they have a chance to catch the ball when the batsman tries to straight-drive a ball.
Some cricketers say that the name ‘silly mid-on’ must be changed to “suicide mid-on” as the silly mid-on will have no chance of escaping when a batsman hits the ball very hard… either the mid-on catches the fast approaching ball in a fraction of a second with his bare hands or the ball hits him hard.

