留守
るす · rusu · JLPT N4 · noun
not at home
🏠🔑 留守 = stay + guard: someone stays to guard the house because the owner is out
Originally 留守 meant the caretaker who stays (留) and guards (守) while the master is away. The meaning slid from the guarding to the reason for it: the owner's absence. Sound hook: rusu — the house keeps a ruse of being occupied.
留 — 卯 (top) + 田 (field)
Originally a phono-semantic compound: 田 (field) suggests staying on the land, with 卯 hinting at the sound. Over time it came to mean 'remain, stay, keep,' as in keeping someone on the land or holding something in place. Modern uses include 留学 (study abroad) and 保留 (retain).
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).'