noun
non-commissioned officer; petty officer
Military term for an enlisted service member who holds a position of authority, such as a sergeant in the army or a petty officer in the navy.
彼は陸軍の下士官として10年勤務した。
He served as a non-commissioned officer in the army for ten years.
海軍では下士官を「ペティオフィサー」と呼ぶ。
In the navy, a petty officer is called a non-commissioned officer.
兵 is a general term for soldiers, including enlisted personnel without command authority, unlike 下士官.
Compound of 下 (lower) + 士官 (officer), literally 'lower officer'. The term is a calque from Western military terminology.