/ Dictionary / Index S SD: Meaning and Definition of Find definitions for: SD Pronunciation: [key] sea-damaged. South Dakota (approved esp. for use with zip code). standard deviation. the intelligence and counterespionage service of the Nazi SS. sd. Pronunciation: [key] sound. S/D Pronunciation: [key] school district. sight draft. S.D. Pronunciation: [key] doctor of science. sea-damaged. senior deacon. South Dakota. special delivery. standard deviation. s.d. Pronunciation: [key] sine die. standard deviation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sd (Thesaurus) Scythian lamb S.D.A. Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language