plural noun Ex·o·cy·cloi·da \ˌek(ˌ)sōˌsīˈklȯidə\

Definition of Exocycloida

  1. :  an order of sea urchins comprising forms with the periproct posterior or oral in position and including the heart urchins and sand dollars

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Origin and Etymology of exocycloida

New Latin, from exo- + cycl- + -oida

Seen and Heard

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a rounded knoll or a ridge of ice

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