A combatant is someone who fights in a war or battle. Soldiers, marines, and naval officers serving in active combat zones are combatants. It specifically refers to people who are directly engaged in fighting, such as those who carry weapons and take part in military operations.

Military forces distinguish between combatants and non-combatants. Combatants are trained fighters who carry weapons and take part in military operations. Non-combatants include medics, chaplains, journalists, and civilians who might be near a war zone but aren't actively fighting. International laws of war require armies to protect non-combatants and treat captured combatants humanely as prisoners of war.

The word can also describe anyone engaged in serious conflict or competition. Two debaters might be called combatants in a championship debate, or rival companies competing fiercely for customers might be described as combatants in a business battle. In these non-military uses, the word emphasizes how intensely the opponents are struggling against each other.

When historians study a battle, they often count how many combatants fought on each side. At the Battle of Gettysburg during the Civil War, roughly 165,000 combatants clashed over three days. Understanding who counts as a combatant helps us grasp the true scale and nature of any conflict.