Definition of archaea in English:


plural noun

  • Microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient group which is intermediate between the bacteria and eukaryotes.

    Also called archaebacteria
    • ‘Participants will also focus on a class of microbes known as the archaea, which literally means ‘ancient.’’
    • ‘Marine plants literally live in a sea of bacteria, archaea, viruses, and fungi - some of which are bound to be pathogenic - yet they seldom get sick.’
    • ‘Bacteria and archaea often clone themselves, trade genes, and in some cases the microbes even merge together into a giant mass of DNA that then gives rise to spores.’
    • ‘Unlike bacteria and archaea, eukaryotes have their DNA in linear pieces that are bound up with special proteins to make chromosomes.’
    • ‘Over the past three decades, bacteria and archaea have been found in some of the most inhospitable places on Earth.’


Modern Latin (plural), from Greek arkhaios ‘primitive’.