From The TimeSplitters Wiki

In TimeSplitters, a Loss is when a player dies, usually by having their health depleted.

Significance in the Games

Dying plays a very important role in TimeSplitters. When a player is killed by another player, in most Arcade modes the player who killed the player gets a point. In Elimination, losses are even more important than kills, as a loss makes the player lose a life. Losses are very bad in Story Mode, as a single loss will cause the player to either restart the mission, or restart from a checkpoint, which is usually far behind the player's progress.
Losses, like kills, are important in measuring the skill of a player. The more losses you have, the worse you are. It is especially ambarassing if you Kill/Loss Rate is low. In the worst cases, you die more often then you kill.

The Effects of a Loss

Losses have many effects, although some of them only apply to certain game modes. The effects are as followss:

• All modes (except Story) - Loss of all Weapons, Powerups, and Armor
• All Deathmatch type modes (only if the scoring setting is Kills-Losses) - The loss of a point
• Elimination and Vampire - The loss of a life (in Vampire also the refilling of your bloodbar)
• Bag Games - Causes you to drop the bag (if your carrying it)
• Gladiator - If your the Gladiator, causes you to lose the power
• Story Mode - Causes you to restart the level or restart from checkpoint

Ways to Suffer a Loss

There are multiple ways to die, although most of them are caused by a loss of Health. Here are the ways to die:

• Getting killed by another player or enemy
• Falling on a Lethal Surface
• Allowing you Bloodlust bar to run out
• Burning
• Getting crushed (i.e. by walls)
• Falling out of level boundaries (very rare)