What is a secret fighter not in uniform?

A secret fighter not in uniform typically refers to an individual who engages in combat or espionage activities without the traditional military attire or identification, often operating covertly. These fighters may work as mercenaries, spies, or part of clandestine operations, making it difficult to identify their allegiance or mission. Their lack of uniform allows for increased anonymity and flexibility in achieving their objectives. This concept is often explored in literature and film, highlighting themes of loyalty, deception, and the moral complexities of warfare.