unsound

un- +‎ sound.

• enPR: ŭn-soundʹ, IPA^(key): /ˌʌnˈsaʊnd/
• Rhymes: -aʊnd

unsound (comparative more unsound or unsounder, superlative most unsound or unsoundest)

1. Not sound, particularly:
   1. Not whole, not solid, defective.
      • 1946 September and October, “Speculation Run Riot”, in Railway Magazine, page 269:

        In the ensuing financial panic, many persons sustained heavy losses, and large numbers of unsound schemes succumbed.

      • 1962 October, Brian Haresnape, “Focus on B.R. passenger stations”, in Modern Railways, page 255:

        A striking example comes to mind, in which a scheme to improve the existing buildings finished up as virtually a complete reconstruction, owing to the unsound condition of the original structure!

      • 2023 March 8, Gareth Dennis, “The Reshaping of things to come...”, in RAIL, number 978, page 47:

        While he is reasonably effusive about inter-city travel, he is heavily disparaging of all types of stopping service, including those on otherwise busy main lines. His analysis is not entirely unsound, and he tackles some of the questions head on.

   2. (especially of equestrianism) Infirm, diseased.
      • 1822, Sir John Comyns, Anthony Hammond, A Digest of the Laws of England‎:

        ... A horse labouring under a temporary injury, capable of being speedily cured, is not unsound within the meaning of a warranty of soundness ...

   3. (UK, especially of people) Not good, unreliable.
      • 1919, P.G. Wodehouse, My Man Jeeves:

        You would not like Nietzsche, sir. He is fundamentally unsound.

• sound

• unsoundly
• unsoundness