plural noun Peri·di·ni·idae \ˌperədə̇ˈnīəˌdē\

Definition of Peridiniidae

  1. :  a family of marine and freshwater dinoflagellates that have a thick test composed of plates and well-marked flagellar grooves — compare ceratium, gonyaulax, peridiniaceae

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Origin and Etymology of peridiniidae

borrowed from New Latin, from Peridinium peridinium + -idae -idae

Seen and Heard

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feeling or affected by lethargy

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