軍事
ぐんじ · gunji · JLPT N1 · noun
personal business
🪖 軍 = army, 事 = affair: army + affair = military affairs
軍 means army and 事 means affair or matter. Together they name the affairs of an army. The reading gun-ji starts with the same sound as the English word gun.
事 — hand 又 holding a banner/tablet on a pole
Originally a pictograph of a hand (又) grasping a pole or ceremonial banner used by an official, depicting the act of conducting court business. From this it came to mean 'affair, matter, business, service.' It shares an ancient origin with 史 (scribe) and 吏 (official).