Combatant
Combatant – a member of the armed forces of a Party to a conflict, even non recognised forces, other than, medical personnel and chaplains, who participates in hostilities. Note: A combatant must be easily recognized through a uniform, a fixed distinctive sign recognizable at a distance and he/she must carry arms openly. Spies and mercenaries are not combatants and are not covered by the rules on prisoners of war.A combatant is engaged in or ready to engage in combat [Merriam-Webster’s Dictionary].
Combatants are persons who are authorized to use force in situations of armed conflict by international humanitarian law. Conversely, they constitute legitimate military targets in times of armed conflict. But, contrary to civilians, they may not be subject to criminal prosecutions for their participation in hostilities as long as their use of force conforms with the provisions of the law of armed conflict, also named humanitarian law.
The use of force may not occur as a result of individual initiative but must take place under a clear chain of responsible command within the framework of respect for the rules of the law of armed conflict. According to the definitions provided by the Geneva Conventions and their first 1977 Additional Protocols, combatants are members of national armed forces or organized groups placed under the effective control of those forces. It is this authorization to use force that distinguishes combatants from civilians.
Combatants can be prosecuted under national or international criminal law if they commit war crimes, crimes against humanity, or acts of genocide, even if they act under the orders of their superiors but not for their plain participation in the hostilities [Médecins Sans Frontières].
Українсько-французько-англійський міжвидовий словник з тактики та логістики. Dictionnaire interamées de termes tactiques et logistiques ukrainien-français-anglais: [в 2-х т.] / Київ. нац. ун-т ім. Тараса Шевченка, Військовий ін-т, Центр розробки Доктрини p.651
Combatants. Médecins Sans Frontières. Retrieved from : https://guide-humanitarian-law.org/content/article/3/combatants/