治安
ちあん · chian · JLPT N1 · noun
order
治 — water radical 氵 + 台 (phonetic)
治 originally referred to the name of a river, written with the water radical 氵 for meaning and 台 as the phonetic component. From 'managing rivers' (flood control), the meaning broadened to 'govern, regulate, manage,' and later 'cure, heal' — all senses of bringing something unruly under control.
安 — roof 宀 + woman 女
A pictographic compound showing a woman 女 under a roof 宀, suggesting safety and tranquility at home. The original meaning 'peaceful, calm, safe' has remained stable since oracle bone script. It later extended to verbs like 'to settle' or 'to install'.