not in good condition; damaged or decayed; an unsound foundation'

not sound financially; unsound banking practices'

containing or based on a fallacy; fallacious reasoning; an unsound argument

[ Syn: fallacious ]

suffering from severe mental illness; of unsound mind

[ Syn: mentally ill , unstable ]

physically unsound or diseased; has a bad back; a bad heart; bad teeth; an unsound limb; unsound teeth

[ Syn: bad , unfit ]

of e.g. advice