archaeon

American  

[ahr-kee-ahn, ahr-kay-ahn] / ɑrˈki ɑn, ɑrˈkeɪ ɑn /

noun

plural

archaeons

1. any member of the domain Archaea, single-celled microorganisms similar to bacteria but having distinct structural and genetic characteristics.

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archaeon Scientific  

/ är′kē-ŏn′ /

plural

archaea

1. Any of a group of microorganisms that resemble bacteria but are different from them in their genetic makeup and certain aspects of their cell structure, such as the composition of their cell walls. Archaea usually live in extreme, often very hot or salty environments, such as hot mineral springs or deep-sea hydrothermal vents, but some are also found in animal digestive systems. The archaea are considered a separate domain in some classifications, but a division of the prokaryotes (Monera) in others. Some scientists believe that archaea were the earliest forms of cellular life.

2. Also called archaebacterium

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Other Word Forms

• archaeal adjective

Example Sentences

The prevailing model holds that eukaryotes arose when an Asgard archaeon formed a symbiotic relationship with an alphaproteobacterium.

From Science Daily • Feb. 20, 2026

In every place, copies of the Borg co-occurred with DNA linked to a methane-oxidizing archaeon called Methanoperedens.

From Science Magazine • Jul. 15, 2021

He is part of a team that spent a decade trying to determine the physical shape of a particular protein in a tiny bacteria-like organism called an archaeon.

From New York Times • Nov. 30, 2020

One archaeon, called Nanoarchaeum equitans, lives as a parasite on another archaeon in near-boiling waters and has dispensed with many of its genes related to energy production and general cellular housekeeping.

From Nature • Jan. 11, 2017

But it’s unclear how the archaeon could have picked up that bacterium.

From Scientific American • Nov. 30, 2015