"Hors de combat" is a term used in international humanitarian law (IHL) which describes a soldier who cannot fight due to being sick, wounded, captured or incapacitated. These soldiers are not allowed to be attacked or harmed because they pose no threat. The rules of IHL state that these individuals are to be treated humanely and protected from harm.
See IHL Basic Principles.
[Last updated in February of 2023 by the Wex Definitions Team]