'Understanding' in the Bible

Surely extortion makes the wise man foolish; and a bribe destroys the understanding.

I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happen to them all.

Yes also, when the fool walks by the way, his understanding fails him, and he says to everyone that he is a fool.