A microscopic organism or particle so small it cannot be seen with a regular microscope without special techniques.
From Greek 'a-' (not) + 'mikron' (small), literally meaning 'not small' but used ironically for things too small to measure ordinarily. The term emerged in early 20th-century microbiology.
This word captures one of science's favorite paradoxes: naming something by what it ISN'T. The prefix 'a-' in Greek often creates words with ironic meanings, like 'atypical' meaning 'not typical' rather than 'slightly typical.'
Complete word intelligence in one call. Free tier — 50 lookups/day.