/ Dictionary / Index N National Transportation Safety Board: Meaning and Definition of Find definitions for: Na'tional Transporta'tion Safe'ty Board" Pronunciation: [key] — U.S. Govt. U.S. Govt. an independent agency, created in 1975, that promotes safe transportation in the U.S. through accident investigations, studies, and recommendations. Abbr.: NTSB Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. National Socialism National War Labor Board Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language