/ Dictionary / Index E equisetoid: Meaning and Definition of Find definitions for: eq•ui•se•toid Pronunciation: (ek"wu-sē'toid), [key] — n. any plant of the phylum or division Equisetophyta (or Sphenopsida), including the horsetails and many extinct species of the Carboniferous Period. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. equirotal equisetum Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language