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

The innovation, detailed in a new study published in the journal Nature Communications, could help aviation meet its target of net-zero carbon emissions by 2050. —Melissa Fleur Afshar, MSNBC Newsweek, 31 Oct. 2025

The move also threatens to make the United States an increasing outlier regarding efforts to lower emissions globally and fight back against climate change, possibly leading to geopolitical shifts. —Nick Thomas, The Washington Examiner, 31 Oct. 2025

That slower growth means that targets to triple global solar capacity by 2030 will probably be missed, and growing demand for energy means emissions are still rising. —Tom Chivers, semafor.com, 31 Oct. 2025

Exxon aims to capture 90% of the carbon dioxide emissions emitted by natural gas plants that power data centers, Woods said. —Spencer Kimball, CNBC, 31 Oct. 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