emission

noun

emis·​sion ē-ˈmi-shən 

1

a

: an act or instance of emitting : emanation

b

archaic : publication

c

: a putting into circulation

2

a

: something sent forth by emitting: such as

(1)

: electromagnetic radiation from an antenna or a celestial body

(2)

usually emissions : substances discharged into the air (as by a smokestack or an automobile engine)

b

: effluvium

emissive

ē-ˈmi-siv 

adjective

Examples of emission in a Sentence

trying to reduce the emission of greenhouse gases

Recent Examples on the Web

Train travel is considered sustainable because of the lower carbon emissions. —Mindy Sink, Denver Post, 7 Dec. 2025

What To Know The volcano showed low-level activity starting in July 2025, including underground magma movement and early sulfur dioxide emissions, according to the Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET), as cited in a NASA report Thursday. —MSNBC Newsweek, 5 Dec. 2025

Satellites capture images of nighttime light emissions that reveal spikes in overall illumination in certain areas, a common phenomenon across the planet when communities break out the holiday lights. —Jill Robbins, Southern Living, 5 Dec. 2025

Modern software development companies offers solutions that combine AI technologies and legacy system modernization to help companies transition to sustainable energy models focused on reducing emissions and efficient resource use. —Atharva Gosavi, Interesting Engineering, 5 Dec. 2025

Word History

First Known Use

1607, in the meaning defined at sense 1a

Phrases Containing emission

• acoustic emission
• positron-emission tomography
• re-emission
• secondary emission

Rhymes for emission

• addition
• admission
• ambition
• attrition
• audition
• clinician
• cognition
• coition
• commission
• condition
• contrition
• dentition

Kids Definition

emission

noun

emis·​sion ē-ˈmish-ən 

1

: an act or instance of emitting

2

: something emitted or discharged

emissive

ē-ˈmis-iv 

adjective

Medical Definition

emission

noun

emis·​sion ē-ˈmish-ən 

1

: an act or instance of emitting

2

a

: something sent forth by emitting: as

(1)

: electrons discharged from a surface

(2)

: electromagnetic waves radiated by an antenna or a celestial body

(3)

: substances and especially pollutants discharged into the air (as by a smokestack or an automobile gasoline engine)

b

: a discharge of fluid from a living body

especially : ejaculate see nocturnal emission