volcanic crater; caldera
Geological term for the opening at the top of a volcano. カルデラ is also used for large calderas.
White smoke is rising from the crater.
The crater of Mt. Fuji is not currently active.
Smoke is rising from the crater.
burner nozzle; burner tip
Technical term for the part of a boiler or furnace where fuel is burned. Often used in industrial contexts.
The burner nozzle of the boiler needs to be cleaned.
The stove's burner nozzle is clogged and hard to light.
The hikers cautiously peered into the crater.
I clean the gas stove's burner nozzles once a month.
カルデラ refers to a large, basin-shaped depression formed by collapse, while 火口 can describe smaller craters or the general summit opening.
火口 specifically means the crater or vent of a volcano, while クレーター is broader and can also describe impact craters on the moon or other planets.
河口 (also read かこう) means the mouth of a river, a completely different concept from 火口's volcanic crater or burner nozzle.
加工 (also read かこう) means processing or manufacturing, unrelated in meaning to 火口's crater or burner sense despite sharing the same sound.
Written identically as 火口, かこう means a volcanic crater, while ひぐち (this entry) means a burner nozzle or the point where a fire started, so context and reading must distinguish them.
口火 (くちび) is a fuse or figurative trigger, while 火口 (かこう) is a volcanic crater or the muzzle of a firearm; the two are easily confused because they share the same kanji in reverse order.
火口 refers to any volcanic crater, while カルデラ specifically means a large crater formed by the collapse of a volcano after an eruption.
Compound of 火 (ka, 'fire') and 口 (kō, 'mouth, opening'). The reading かこう is the on'yomi of both characters.