爆発
ばくはつ · bakuhatsu · JLPT N3 · noun
explosion
💣🌋 爆発 = burst + set off: a burst that is released outward
爆 (baku) means burst or explode, as in 爆弾 bakudan, bomb. 発 (hatsu) means to emit or set off, as in 出発 shuppatsu, departure. Put a burst together with a release and you get an explosion, or a volcano's eruption.
爆 — fire 火 + 暴 (violent/sudden, phonetic)
A semantic-phonetic compound: 火 (fire) gives the meaning, while 暴 (sudden, violent) supplies the sound and reinforces the sense. Originally meant to burst or explode with fire, later extended to any sudden, forceful eruption like popping or bursting.