ac·​ri·​tarch ˈa-kri-ˌtärk How to pronounce acritarch (audio)
: 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

Word History


Greek ákritos "confused, uncertain" (from a- a- entry 2 + kritós, verbal adjective of krī́nein "to separate, decide") + archḗ "beginning" — more at certain entry 1, arch- entry 1

First Known Use

1963, in the meaning defined above

Time Traveler
The first known use of acritarch was in 1963

Dictionary Entries Near acritarch

Cite this Entry

“Acritarch.” Dictionary, Merriam-Webster, Accessed 22 Sep. 2023.

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