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

Schwarzenegger, his former boss, ushered in the state’s landmark cap-and-invest program, which aims to reduce planet-warming emissions. — Los Angeles Times, 5 Nov. 2026

At the same time, federal agencies have rolled back numerous anti-climate change measures in moves that critics say leave the country more vulnerable to warming and emissions. — Adam Kovac, Scientific American, 4 Nov. 2026

The Colorado Energy Office told the Public Utilities Commission that 600,000 homes would need to be converted from gas to fully electric to meet the new Clean Heat Plan's 41% emission reduction goal. — Jennifer McRae, CBS News, 4 Nov. 2026

Indiana’s air quality had improved dramatically since 2000, with sulfur dioxide emissions down 96%, nitrogen oxide down 84% and carbon dioxide down 35%. — Doug Ross, Chicago Tribune, 3 Nov. 2026

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