/ Dictionary / Index S SSBN: Meaning and Definition of Find definitions for: SSBN Pronunciation: [key] the U.S. Navy designation for the fleet ballistic missile submarine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. SSB SSC Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language