/ Dictionary / Index U unsound: Meaning and Definition of Find definitions for: un•sound Pronunciation: (un-sound'), [key] — -er, -est. not sound; unhealthy, diseased, or disordered, as the body or mind. decayed or impaired, as timber or foods; defective. not solid or firm, as foundations. not well-founded or valid; fallacious: an unsound argument. easily broken; light: unsound slumber. not financially strong; unreliable: an unsound corporation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unsound (Thesaurus) unsophisticated unsparing Related Content Daily Word Quiz: opulent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language