A microorganism -LRB- from the , mikrós , `` small '' and , organismós , `` organism '' ; also spelled micro organism or micro-organism -RRB- or microbe is an organism that is microscopic -LRB- usually too small to be seen by the naked human eye -RRB- .

A microorganism or microbe is a living thing -LRB- organism -RRB- that is too small to be visible to the human eye -LRB- microscopic -RRB- .
