災害
さいがい · saigai · JLPT N1 · noun
disaster
🔥🌊 災 = fire + flood sign, 害 = harm; together: fire-and-flood harm = disaster
災 is built from 火 (fire) and 巛 (flowing water), the original calamities being fire and flood. 害 means harm, so 災害 names any destructive event.
害 — 宀 roof + 丯 (phonetic) + 口 mouth
Originally an ideograph showing harm spoken under a roof, with 宀 (roof/house) on top, a phonetic element 丯 in the middle, and 口 (mouth) below suggesting harmful speech. Over time it shifted from 'injury caused by words' to the broader senses of 'harm,' 'injure,' and 'fear.'