noun sphae·rid·i·um \-ēəm\

Definition of sphaeridium



  1. :  one of the small organs found on or buried in the test of all recent sea urchins except the Cidaroida suggesting statoliths in structure and possibly subserving a similar function

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Origin and Etymology of sphaeridium

New Latin, from sphaer- + -idium

Seen and Heard

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a trip made at another's expense

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