守る
まもる · mamoru · JLPT N3 · verb-godan
to protect
🛡️ 守 = roof 宀 + hand 寸: a hand on guard under the roof
The same verb covers keeping rules and promises: 約束を守る means to keep a promise, and ルールを守る means to follow the rules. Protecting something and abiding by it both mean holding it safe and not letting it break.
守 — roof 宀 + hand/measure 寸
Originally depicts a hand (寸) under a roof (宀), suggesting someone guarding or maintaining a household. The combination evokes the idea of holding or keeping watch over a place. From this concrete image of guarding a home, the meaning broadened to 'guard,' 'protect,' 'keep,' and 'observe (rules).'