Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

endosymbiosis

play
noun en·do·sym·bi·o·sis \ˌen-dō-ˌsim-bī-ˈō-səs, -bē-\

Definition of endosymbiosis

  1. :  symbiosis in which a symbiont dwells within the body of its symbiotic partner

endosymbiont

play \ˌen-dō-ˈsim-bī-ˌänt, -bē-\ noun

endosymbiotic

play \ˌen-dō-ˌsim-bī-ˈä-tik, -bē-\ adjective

Indulge Your Inner Word Nerd

alt-594ab41a604d2
Trending: Kim and Kanye Might Have Hired a Surrogate Mother
image599301899
Pretty in 'Pink'
alt-594d2b6325245
'Pride': The Word That Went From Vice to Strength
istock-refers-to-this-as-a-tumble-of-strawberries-which-sounded-pretty-nice-to-us
June 2017 Words of the Day Quiz

1932

First Known Use of endosymbiosis

1932

Medical Dictionary

endosymbiosis

play play
noun en·do·sym·bi·o·sis \ˌen-dō-ˌsim-bī-ˈō-səs, -bē-\

Medical Definition of endosymbiosis

plural

endosymbioses

\-ˌsēz\play

  1. :  symbiosis in which a symbiotic organism lives within the body of its partner

endosymbiotic

\-ˈät-ik\play play adjective

Learn More about endosymbiosis

  1. Britannica.com: Encyclopedia article about endosymbiosis

Seen and Heard

What made you want to look up endosymbiosis? 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

volplane

play

to glide in or as if in an airplane

Get Word of the Day daily email!

TRENDING NOW

  1. surrogate mother From TMZ to the dictionary.

  2. zealot A fanatical partisan

  3. stonewall to be uncooperative, obstructive, or evasive

  4. scurrilous Containing obscenities, abuse, or slander

  5. depose That word might not mean what you think it means.

SEE ALL

BROWSE DICTIONARY

endosymbiosis

WORD GAMES

Take a 3-minute break and test your skills!

  • istock-refers-to-this-as-a-tumble-of-strawberries-which-sounded-pretty-nice-to-us
  • Which is a synonym of garner?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Word Winder's CrossWinder

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-594d2b6325245
'Pride': The Word That Went From Vice to Strength

Do you take pride in Pride?

image599301899
Pink: The Color that Will Change Your Life

From Fuchsia to Baker-Miller Pink

image2144101468
That Sucks Word Alternatives

Your day is the worst. Your vocabulary is the best.

alt-5931949575ca5
'All the Feels,' All the Time

Once more, with 'feels'

Ask the Editors

decimate-video
Is it wrong to use 'decimate' to mean 'destroy'?

Language changes

serial-comma
The Serial Comma

Why don't they call it the Merriam-Webster comma?

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

istock-refers-to-this-as-a-tumble-of-strawberries-which-sounded-pretty-nice-to-us
June 2017 Words of the Day Quiz

Summer's first WOTD quiz.

Take the quiz
alt-5941ad7527c3c
Yearbook Superlatives Quiz

Is that your picture under "Largest Vocabulary"?

Take the quiz
True or False
True or False?

Test your knowledge - and maybe learn something along the way.

Take the quiz
Word Winder's CrossWinder
Word Winder's CrossWinder

A game of winding words.

Play the game