Wicket

In cricket, a wicket is:
Object.
There is one wicket in each of the two batsmen's grounds. The fielding team can hit a wicket with the ball to run out a batsman, but only if there is no batsman in the ground of the wicket. In addition, when delivering the ball to the batsman, the bowler can hit the wicket in the striker's ground with the ball to bowl the striker out.
The wicket is said to have been "put down" when any of its 5 sticks fall to the ground because it was hit by the ball or a player holding the ball. The sticks can be put back in place and then hit back off to put the wicket down more than once.
Sides of the field.
The field can be defined as having two halves: the "off side" and the "leg side"/"on side", with these being separated by an imaginary line connecting the middle stump of both wickets. The off side of the field is the right side of a field for a right-handed batsman who is looking at the bowler, and the leg side is the left side. (This is reversed for a left-handed batsman.)
Batsman getting out.
A batsman is said to have "lost his wicket" when he gets out.