People who try to stop someone from moving forward in sports by grabbing them.
Tacklers are important in sports like football and rugby.
Examples:
The tacklers tried to stop the running back from getting a touchdown.
The tacklers tackled the player with the ball.
The tacklers are very strong and fast.
The tacklers are like walls, they stop everyone.
The tacklers are like hungry lions, they want to catch the players.
The tacklers are the heroes of the defense team.