/ Dictionary / Index S septi-: Meaning and Definition of Find definitions for: septi- Pronunciation: [key] a combining form meaning “seven,” used in the formation of compound words: septilateral. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. septet septic Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language