monera

noun (used with a plural verb) Biology.

1. a taxonomic kingdom of prokaryotic organisms that typically reproduce by asexual budding or fission and have a nutritional mode of absorption, photosynthesis, or chemosynthesis, comprising the bacteria, blue-green algae, and various primitive pathogens.

The kingdom of single-celled organisms without a cell nucleus (see also prokaryotes). Monera are the most primitive living things and are thought to have been the first to evolve.