/ Dictionary / Index S septum: Meaning and Definition of Find definitions for: sep•tum Pronunciation: (sep'tum), [key] — pl. -ta a dividing wall, membrane, or the like, in a plant or animal structure; dissepiment. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: septum (Thesaurus) Septuagint septuple Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language