/ Dictionary / Index E equisetum: Meaning and Definition of Find definitions for: eq•ui•se•tum Pronunciation: (ek"wu-sē'tum), [key] — pl. -tums, -ta any plant of the genus Equisetum, comprising the horsetails. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: equisetum (Thesaurus) equisetoid equitable 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