Elimination is a game mode that involves players playing against eachother in rounds, using teamwork and coordination to stay alive and kill the enemy to win.
Elimination is a rarely played game mode in which players play in rounds against eachother. Each time a player dies in a round, they will be dead for that round, then revive once: 1) the time ran out and the next round starts, 2) one of the teams kills all of the other teams members and the next round starts. Match time is around 2:30 and was a competitive game-mode. This game mode was played on Haunt, TPile, and Snowy Canyon, but is on more other maps.
Most competitive matches (also known as Clan Wars) are played in this game mode generally. Team Death Match (known as TDM on "Warmerise") is sometimes chosen over Elimination. Elimination is good for competitive play, because it limits your lives and your skill when it comes to running and gunning down your enemies. Tactics and callouts are used to help other team-mates out for knowing where enemy players are, or to hold a defensive position on a map.