meio- Also mio-.
Less or fewer.
[Greek meiōn, less or smaller.]
Meiosis is cell division that results in two daughter cells each with half the chromosome number of the parent cell; meiofauna are minute animals living in soil and aquatic sediments; meiobenthos (Greek benthos, depth of the sea) are small organisms living at the bottom of the sea.
Mio- is an alternative spelling, as in Miocene (Greek kainos, new, so literally ‘the lesser new [period]’), relating to the fourth epoch of the Tertiary period, between the Oligocene and Pliocene epochs; or miogeoclinal (less often miogeosynclinal), of a geosyncline that is situated between a larger, volcanic one and a stable area of the crust.
The medical term miosis for an excessive constriction of the pupil of the eye comes instead from Greek muein, to shut the eyes.