A soldier is a person who serves as part of an army. A soldier can be a conscripted or volunteer enlisted person, a non-commissioned officer, a warrant officer, or an officer. Soldiers may be involved directly in armed hostilities, such as members of infantry, artillery, or armored units, or as personnel serving in support roles that rarely see actual combat. Etymology. The word soldier derives from the Middle English word soudeour, from Old French soudeer or soudeour, meaning mercenary, from soudee, meaning shilling's worth or wage, from sou or soud, shilling.
https://en.wikipedia.org/wiki/Soldier