a combining form with the meanings "small" ( microcosm; microgamete ), "very small in comparison with others of its kind" ( microcassette; microlith ), "too small to be seen by the unaided eye" ( microfossil; microorganism ), "dealing with extremely minute organisms, organic structures, or quantities of a substance" ( microdissection; microscope ), "localized, restricted in scope or area" ( microburst; microhabitat ), "(of a discipline) focusing on a restricted area" ( microeconomics ), "containing or dealing with texts that require enlargement to be read" ( microfilm; microreader ), "one millionth" ( microgram ).
Also, esp. before a vowel, micr- .
[ mikrós small ]