/ Dictionary / Index T tail fin: Meaning and Definition of Find definitions for: tail' fin". Pronunciation: [key] See See under (def. 7). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tailfin (Thesaurus) tail fan tailfirst Related Content Daily Word Quiz: pristine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language