Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

acritarch

play
noun ac·ri·tarch \ˈa-kri-ˌtärk\

Definition of acritarch

  1. :  any of a group of fossil one-celled marine planktonic organisms of uncertain and possibly various taxonomic affinities held to represent the earliest known eukaryotes



Origin of acritarch

Greek akritos uncertain (from a- + kritos, verbal of krinein to decide) + archē beginning — more at certain, arch-


First Known Use: 1963


Learn More about acritarch


Seen and Heard

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

WORD OF THE DAY

February 14, 2016

to hug and kiss another person

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image33683556

How much does a batman (the Turkish unit of measurement) weigh?

100 pounds 16.96 pounds 196.5 pounds 2.2 pounds
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

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

TAKE THE QUIZ