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

To reduce transport emissions, the resort sources many of its ingredients locally, which is denoted with the initials LS on menus. —Kathryn Romeyn, Travel + Leisure, 28 Sep. 2025

By studying the region with narrowband filters sensitive to hydrogen (H-alpha) and sulfur (S II) emissions, the team detected a coherent, circular shell structure centered on the nova. —Rupendra Brahambhatt, Interesting Engineering, 27 Sep. 2025

As the planet continues to warm, melting ice caps and expanding the volume of sea water, scientists project bay waters will rise nearly another foot by 2050 and 3 feet or more by 2100, depending on how much emissions of fossil fuels rise or fall over the next 75 years worldwide. —Paul Rogers, Mercury News, 26 Sep. 2025

Production at the company’s mill grew 124 percent, but carbon emissions and electricity consumption decreased 18 percent, respectively. —Angela Velasquez, Sourcing Journal, 26 Sep. 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