unsound

1. Not sound, particularly:Examples: "unsound mind"; "In the ensuing financial panic, many persons sustained heavy losses, and large numbers of unsound schemes succumbed."; "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!"

2. Not sound, particularly:Examples: "... A horse labouring under a temporary injury, capable of being speedily cured, is not unsound within the meaning of a warranty of soundness ..."especially

3. Not sound, particularly:Examples: "You would not like Nietzsche, sir. He is fundamentally unsound."UKespecially