A member of the armed forces who does not participate in combat (e.g. a chaplain or surgeon) WordNet 3.0 & Open English WordNet

Non-combatant is a term of art in the law of war and international humanitarian law to refer to civilians who are not taking a direct part in hostilities; persons, such as combat medics and military chaplains, who are members of the belligerent armed forces but are protected because of their specific duties ; combatants who are placed hors de combat; and neutral persons, such as peacekeepers, who are not involved in fighting for one of the belligerents involved in a war. Wikipedia

Civilian who does not take a direct part in hostilities during war Wikidata

A non-fighting member of the armed forces. Wiktionary