His comments were rather unintelligent and showed a lack of understanding.

Seine Kommentare waren ziemlich unintelligent und zeigten einen Mangel an Verständnis.

It was an unintelligent decision to invest all his savings in that risky venture.

Es war eine unintelligente Entscheidung, all seine Ersparnisse in dieses riskante Unternehmen zu investieren.