prokaryote

Any of various microorganisms of the domains Archaea and Bacteria, characterized by the absence of a distinct membrane-bound nucleus and membrane-bound organelles and by the simultaneous occurrence of DNA transcription and protein synthesis at the same site, in contrast to eukaryotes.

An organism whose cell (or cells) are characterized by the absence of a nucleus or any other membrane–bound organelles.

In the two-empire system of biological taxonomy, an organism of the kingdom Prokaryotae (now superseded).

a unicellular organism having cells lacking membrane-bound nuclei; bacteria are the prime example but also included are blue-green algae and actinomycetes and mycoplasma