Translation guide
The English word "eruption" covers several distinct concepts in Japanese. The most common uses are for volcanic eruptions, skin breakouts, and sudden outbursts of emotion or violence. Each meaning has its own natural Japanese expressions.
Describing a volcano erupting, including lava, ash, and pyroclastic flows.
The standard word for a volcanic eruption. Used as both a noun and a suru-verb (噴火する).
桜島が噴火した。
Sakurajima erupted.
大規模な噴火が予想される。
A large-scale eruption is expected.
Means 'explosion' and can be used for explosive volcanic eruptions, but is broader and not specific to volcanoes.
Referring to a sudden outbreak of spots, pimples, or a rash on the skin.
Describing a sudden, intense expression of emotion, violence, or conflict.
Describing the eruption of water or steam from a geyser or hot spring.
Referring to a tooth breaking through the gum.
The standard verb for teeth coming in or erupting. Used for both baby teeth and permanent teeth.
噴火 (ふんか) specifically means volcanic eruption, while 爆発 (ばくはつ) means explosion. For a volcanic eruption, 噴火 is the standard term. 爆発 can be used if the eruption is particularly explosive, but it is less precise.
噴火 is only for volcanic eruptions. Using it for skin breakouts or emotional outbursts would sound very strange and unnatural.
富士山の噴火は大きな懸念事項です。
The eruption of Mount Fuji is a major concern.
火山が爆発した。
The volcano exploded.
Medical term for a skin eruption or rash. Can be used as a noun or suru-verb (発疹する).
体中に発疹が出た。
I broke out in a rash all over my body.
Common word for pimples or skin eruptions, especially on the face. More casual than 発疹.
顔に吹き出物ができた。
I got a pimple on my face.
Specifically refers to eczema or dermatitis, a type of skin eruption with inflammation.
湿疹がひどくてかゆい。
The eczema is severe and itchy.
Used for the sudden outbreak of war, conflict, or violence. Often used in news reports.
Can metaphorically mean an outburst of emotion, like anger or laughter. Often used as 爆発する.
Means 'sudden occurrence' or 'outbreak', often used for unexpected events or actions.
突発的な暴力行為。
A sudden eruption of violence.
Means 'gushing out' or 'spewing', used for water, steam, or gas erupting from the ground.
間欠泉が噴出した。
The geyser erupted.
歯が生えてきた。
A tooth is erupting.
Dental term for tooth eruption, used in technical contexts.
歯の萌出が遅れている。
Tooth eruption is delayed.
She had an eruption of pimples on her forehead.
突然の暴力の勃発に皆が驚いた。
The sudden eruption of violence shocked everyone.