Mercenary a person who takes part in an armed conflict and is motivated to take part in the hostilities essentially by the desire for private gain and, in fact, is promised, by or on behalf of a Party to the conflict, material compensation substantially in excess of that promised or paid to combatants of similar ranks and functions in the armed forces of that Party. When the term "mercenary" is used to refer to a soldier of a national, regular army, it usually considered to have pejorative connotations.