adj. 1 unhealthy, diseased. 2 rotten, weak. 3 a ill-founded, fallacious. b unorthodox, heretical. 4 unreliable. 5 wicked. of unsound mind insane. unsoundly adv. unsoundness n.
UNSOUND
Meaning of UNSOUND in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012