Definition of Protococcus

: a genus of unicellular globose chiefly terrestrial green algae (family Protococcaceae) that in former classifications included most such aerial algae but is now usually restricted to forms with a single large peripheral cloroplast that divide in two planes to form thin filmy colonies (as on damp rocks or the bark of trees) — compare chlorococcum

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!

History and Etymology for Protococcus

New Latin, from prot- + -coccus

Keep scrolling for more

Learn More about Protococcus

Statistics for Protococcus

Cite this Entry

“Protococcus.” Dictionary, Merriam-Webster, Accessed 14 Jul. 2020.

Comments on Protococcus

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


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

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!