/ Dictionary / Index A aqueduct of Sylvius: Meaning and Definition of Find definitions for: aq'ueduct of Syl'vi•us Pronunciation: (sil'vē-us), [key] — Anat. Anat. a canal in the midbrain, connecting the third and fourth ventricles of the brain. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aqueduct aqueous Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language