/ Dictionary / Index S Sylvian fissure: Meaning and Definition of Find definitions for: Syl'vi•an fis'sure Pronunciation: (sil'vē-un), [key] — Anat. Anat. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Sylvia sylvic acid Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language