火口
かこう · kakou · JLPT N2 · noun
volcanic crater
🌋 火口 = 火 fire + 口 mouth: the mouth of a volcano, where the fire comes out
火 means fire and 口 means mouth. A crater is the mouth at the top of a volcano, where lava and gas escape.
火 — pictograph of flames rising
火 is a pictograph showing flames rising upward from a fire, with the central stroke as the main blaze and the side strokes as sparks. The ancient oracle bone form looked even more clearly like a burning flame. It still means 'fire' today and serves as a common radical in characters related to heat, burning, or cooking.
口 — pictograph of an open mouth
口 is one of the oldest pictographs in Chinese, originally drawn as a simple outline of an open mouth. Its core meaning 'mouth' extended naturally to 'opening' or 'entrance', as in 入口 (entrance). It also serves as a common radical in characters related to speech, eating, or apertures.