noun Me·rid·i·on \mə̇ˈridēˌän\

Definition of Meridion

  1. :  a genus (coextensive with the family Meridionaceae) of freshwater pennate diatoms having cuneate cells arranged in flat, fan-shaped, or spiral colonies and often causing odors in public water supplies

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Origin and Etymology of meridion

New Latin, from Greek, diminutive of merid-, meris part, portion — more at merit

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