Dictionary / Vocabulary / たちが悪い
たちがわるい
of bad character; ill-natured; nasty; vicious
Also written タチが悪い、質が悪い、性質が悪い
自分が賢いと信じている間抜けは、むしろただの間抜けよりも質が悪い。
A nudnik who believes he's profound is even worse than just a plain nudnik.