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

Microsoft announced recently that its emissions from carbon dioxide had surged nearly 30% since 2020 due to the expansion of its data centers, which are powered by oil and gas. —Anand Rao, Fortune, 16 Aug. 2025

Adaptive reuse also offers substantial environmental benefits by minimizing demolition waste, reducing carbon emissions and supporting more sustainable urban planning. —Dr. Dick Bridy, Forbes.com, 15 Aug. 2025

This showed that the shifts in the PDO were driven by an interplay of increasing warming from greenhouse gas emissions and cooling from sun-blocking particles called aerosols that are associated with industrial pollution. —Pedro Dinezio, The Conversation, 13 Aug. 2025

About 21 percent of Indiana's total emissions come from the state’s transportation sector. —Sophie Hartley, IndyStar, 13 Aug. 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