| Noun | 1. | division Archaebacteria - in some classifications considered a kingdom kingdom Monera, kingdom Prokaryotae, Monera, Prokayotae - prokaryotic bacteria and blue-green algae and various primitive pathogens; because of lack of consensus on how to divide the organisms into phyla informal names are used for the major divisions archaebacteria, archaebacterium, archaeobacteria, archeobacteria - considered ancient life forms that evolved separately from bacteria and blue-green algae division - (biology) a group of organisms forming a subdivision of a larger category |