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

David McNew / Getty Images Marquez helped convert Pasadena's fire fleet to renewable diesel fuel so that his crews wouldn't keep breathing in the emissions from idling trucks. —Kara Finnstrom, CBS News, 5 Jan. 2026

By keeping more carbon in the final product, the new process not only cuts emissions but also increases yield and ultimately improves its economics. —Christopher McFadden, Interesting Engineering, 4 Jan. 2026

Experts say that the importance of global action to reduce planet-warming emissions cannot be overstated. —Simmone Shah, Time, 1 Jan. 2026

With the Tesla Semi within its fleet, DHL can further accelerate its transition to net zero-emission logistics, a call the logistics giant aims to reach by 2050. —Glenn Taylor, Sourcing Journal, 31 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