mac·​ro·​organism | \ ¦makrō+ \

Definition of macroorganism

: an organism large enough to be seen by the normal unaided human eye — compare microorganism

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

First Known Use of macroorganism

1900, in the meaning defined above

History and Etymology for macroorganism

macr- + organism

Keep scrolling for more

Learn More about macroorganism

Time Traveler for macroorganism

Time Traveler

The first known use of macroorganism was in 1900

See more words from the same year

Statistics for macroorganism

Cite this Entry

“Macroorganism.” The Dictionary, Merriam-Webster Inc., Accessed 24 January 2020.

Comments on macroorganism

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


a feeling of well-being or elation

Get Word of the Day daily email!

Test Your Vocabulary

Intact Latin Quiz

  • roman tablet
  • What did focus mean in Latin?
Spell It

Can you spell these 10 commonly misspelled words?

Syn City

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

Love words? Need even more definitions?

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