'non-combatant' originates from the prefix 'non-' (from Latin 'non', meaning 'not') combined with 'combatant', which comes from French 'combatant' (present participle of 'combattre') and ultimately from Late Latin/Italian roots related to fighting.

'combatant' developed from Old French 'combattant' (present participle of 'combattre') and from Vulgar/Late Latin forms based on 'combattere'/'com-battere' ('to fight'), and 'non-' was added in English to form 'non-combatant' to denote someone 'not taking part in combat'.

Initially, 'combatant' meant 'one who fights'; adding the prefix 'non-' originally meant 'not a fighter' and this meaning has remained stable to refer to persons or roles not engaged in combat.