Which best describes a mercenary?

A mercenary is best described as a professional soldier who is hired by a foreign army. This definition highlights the primary characteristic of mercenaries: their service is motivated by financial gain rather than allegiance to a nation or a cause. Unlike soldiers who are loyal to their own country's military forces, mercenaries often operate independently or are employed by governments or groups that require military expertise. They may fight in conflicts that are not directly tied to their own national interests, which further distinguishes them from regular soldiers serving for patriotic reasons or a specific ideology. This role can often place mercenaries in ethically complex situations, as they may engage in warfare for the highest bidder rather than for ideals such as justice or national loyalty.