1. Plural of archaean; members of the domain Archaea, a group of single-celled microorganisms that are genetically distinct from bacteria and eukaryotes.
Usage: scientific; biology; also spelled 'archeans'

Examples

• Archaeans thrive in extreme environments such as hot springs and salt lakes.
• Scientists discovered that archaeans are more closely related to eukaryotes than to bacteria.
• Many archaeans produce methane as a byproduct of their metabolism.
• The study of archaeans has revealed new insights into the early history of life on Earth.
• Archaeans can survive in conditions that would be lethal to most other organisms.