Translation guide
To send out or release something such as light, heat, sound, gas, or radiation. Japanese uses different verbs depending on what is being emitted.
To give off light, warmth, or electromagnetic waves
General verb for emitting light, heat, or energy. Often used in written or formal contexts.
太陽は光と熱を放つ。
The sun emits light and heat.
Common for emitting light, sound, or signals. Slightly formal.
そのランプは柔らかい光を発する。
The lamp emits a soft light.
Everyday verb for putting out light, heat, or sound. Very common in casual speech.
ストーブが暖かい空気を出している。
The heater is emitting warm air.
To produce a sound, cry, or utterance
Standard for emitting sounds, especially in descriptions.
その機械は奇妙な音を発した。
The machine emitted a strange sound.
Casual and common for making sounds.
彼はため息を出した。
He emitted a sigh.
Used for loud or piercing sounds, often in literary contexts.
To release a gas, fume, or odor
Most common for emitting smoke, gas, or smells in everyday language.
車が排気ガスを出している。
The car is emitting exhaust fumes.
Formal or technical term for releasing substances into the environment.
工場が有害物質を放出した。
The factory emitted hazardous substances.
Can be used for smells, but less common than 出す.
To release subatomic particles or electromagnetic radiation
Technical term for emitting radiation or particles.
ウランは放射線を放射する。
Uranium emits radiation.
Used in physics for emission of particles or energy.
原子核が中性子を放出する。
The atomic nucleus emits neutrons.
出す is the most general and casual verb for emitting something. 発する is slightly more formal and often used for light, sound, or signals. 放つ implies a stronger, more forceful emission and is common in written or literary language.
English 'emit' is often translated directly as エミットする in technical contexts, but this is not natural Japanese. Use the verbs above depending on what is emitted.
The siren emitted a sharp sound.
花が甘い香りを発している。
The flowers are emitting a sweet fragrance.