n., pl., ar·chae·a (-kē-ə).
Any of various single-celled prokaryotes genetically distinct from bacteria, often thriving in extreme environmental conditions.
[New Latin, from Greek arkhaion, neuter singular of arkhaios, ancient. See archaic.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
