Emily Dickinson Lexicon

SPHE-ROID', n. [Gr. σφαιρα, a sphere, and ειδος, form.]

A body or figure approaching to a sphere, but not perfectly spherical. A spheroid is oblate or prolate. The earth found to be an oblate spheroid, that is, flatted at the poles whereas some astronomers formerly supposed it to be prolate or oblong.