及物动词

1. 发出，排放，散发（热、光、气或气味）
If something emits heat, light, gas, or a smell, it produces it and sends it out by means of a physical or chemical process.

2. 发出（声音或噪音）
To emit a sound or noise means to produce it.

1. expel (gases or odors)

Synonym: breathepass off

2. express audibly
utter sounds (not necessarily words)

e.g. She let out a big heavy sigh
He uttered strange sounds that nobody could understand

Synonym: utterlet outlet loose

3. give off, send forth, or discharge
as of light, heat, or radiation, vapor, etc.

e.g. The ozone layer blocks some harmful rays which the sun emits

Synonym: give outgive off