What does emit mean?
Emit is a transitive verb meaning to send out or discharge something — typically light, heat, sound, gas, or a smell — from an internal source into the surrounding environment. A fire emits warmth, a radio antenna emits signals, a factory may emit pollutants, and a person might emit a laugh or a sigh. The word carries a neutral-to-formal tone and appears frequently in scientific and environmental writing, where phrases like "emit carbon" or "emit radiation" are standard. Its Latin root, emittere, means literally to send out, combining e- (out) with mittere (to send). Related forms include the noun emission, the noun agent emitter, and the adjective emissive. Because it describes release rather than containment, its natural opposites include absorb and take in. Emit remains a precise, versatile verb wherever something is given off from within.
verbTo emit is to send out or give off something such as light, heat, sound, gas, or a smell, whether naturally or deliberately.
- To give off or discharge (light, heat, sound, gas, or an odor), as from a source or body
- To utter or voice (a sound, cry, or words)
"The old furnace emitted a steady hum that could be heard throughout the house."
"The lighthouse emitted a powerful beam of light across the dark water."
"She emitted a small sigh of relief when the results came in."
Every breath you exhale emits carbon dioxide — and so does every cow, volcano, and car on Earth, making "emit" one of the most consequential verbs in climate science.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of emit
Emit derives directly from Latin emittere, formed from e- (out) plus mittere (to send), meaning "to send out." It entered English in the early 17th century, initially in scientific and philosophical writing before broadening to general use. It shares this Latin root with related English words such as mission, remission, and transmission, all built on the same stem mittere.
Related word forms
How emit is actually used
Formal to neutral in register; common in scientific, environmental, and technical contexts. The past tense and past participle are "emitted" (with the consonant doubled). Often used with physical phenomena in technical writing but also acceptable for sounds or sighs in ordinary speech.
Easily confused with emit
"Emit" means to send something out, while "omit" means to leave something out or fail to include it.