Akademik

unsound

adj.
1 unhealthy, diseased.
2 rotten, weak.
3 a ill-founded, fallacious. b unorthodox, heretical.
4 unreliable.
5 wicked.
Phrases and idioms:
of unsound mind insane.
Derivatives:
unsoundly adv. unsoundness n.

Useful english dictionary. 2012.