/ Dictionary / Index S Securities Exchange Act: Meaning and Definition of Find definitions for: Secu'rities Exchange' Act" Pronunciation: [key] — U.S. Govt. U.S. Govt. a law passed in 1934 establishing the SEC. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Securities and Exchange Commission security Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language