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

These results are in line with previous infrared observations of quasars, feeding supermassive black holes that glow brightly due to vast emissions of energy from material surrounding the black hole. —Robert Lea, Space.com, 14 Nov. 2025

City officials argue building housing near public transit helps energize neglected neighborhoods and provide affordable housing, while ensuring a steady stream of riders for transit systems and cutting greenhouse gas emissions by reducing the number of cars on the road. —Preston Fore, Fortune, 14 Nov. 2025

Animal agriculture has been tied to issues such as deforestation and high greenhouse gas emissions, so vegan collagen can be a more eco-friendly option. —Lindsay Curtis, Health, 14 Nov. 2025

Each year a slew of reports are published to coincide with COP, stressing the huge impact of extreme weather on African countries while pointing out that the continent only contributes about 4% of global carbon emissions. —Alexis Akwagyiram, semafor.com, 14 Nov. 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