Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

emissivity

play
noun emis·siv·i·ty \ˌe-mə-ˈsi-və-tē, ˌē-ˌmi-ˈsi-\

Definition of emissivity

plural

emissivities

  1. :  the relative power of a surface to emit heat by radiation :  the ratio of the radiant energy emitted by a surface to that emitted by a blackbody at the same temperature

From the M-W Editors

alt-59760690a61d7
Trending: Trump Tweets, We Define: 'Beleaguered'
video-title-words-of-the-year-1066
Words of the Year: 1066
emoji-the-quiz
The Emoji Quiz
alt-596f95fe451e7
'Drought' & 'Drouth' Take Us Back In Time

First Known Use of emissivity

1880

Medical Dictionary

emissivity

play play
noun emis·siv·i·ty \ˌem-ə-ˈsiv-ət-ē, ˌē-ˌmis-ˈiv-\

Medical Definition of emissivity

plural

emissivities

  1. :  the relative power of a surface to emit heat by radiation :  the ratio of the radiant energy emitted by a surface to that emitted by a blackbody at the same temperature

Learn More about emissivity

  1. See words that rhyme with emissivity

Seen and Heard

What made you want to look up emissivity? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

wreak

play

to bring about or cause (something)

Get Word of the Day daily email!

TRENDING NOW

  1. beleaguer 'Being subjected to constant or repeated trouble or harassment'

  2. scaramouch A new White House communications director

  3. non sequitur “It does not follow”

  4. admiral's mast A massive search ends with an 'admiral's mast'.

  5. calumny 'An untrue statement that is made to damage someone's reputation'

SEE ALL

BROWSE DICTIONARY

emissivity

Test Your Vocabulary

The Emoji Quiz

  • emoji-the-quiz
  • What phase of the moon is this: 🌖 ?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

alt-596f95fe451e7
'Drought' & 'Drouth' Take Us Back In Time

A variant spelling with a long history

alt-59721dd897313
The 'Best' Way to Sign Off On An E-mail

Give them your best

image386126722
Words and Phrases That Come from the Dinner Table

Fill your plate with these surprising food words

ghost-being-disinvited-from-party
'Disinvite' or 'Uninvite'?

A disinvited guest is an uninvited problem

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

emoji-the-quiz
The Emoji Quiz

Think you’re an emoji 👓 expert? Let’s see 🤔

Take the quiz
image941935269
A Game of Thrones Word Quiz

In the Game of Thrones quiz, you learn some new vocabulary. (It’s quite safe, really. You will not die.)

Take the quiz
Name That Thing
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Take the quiz
SCRABBLE® Sprint
SCRABBLE® Sprint

SCRABBLE® fans, sharpen your skills!

Play the game