'Foolish' in the Bible

From which some have been turned away, giving themselves to foolish talking;

But have nothing to do with unclean and foolish stories. Give yourself training in religion:

But they that will be rich fall into temptation and a snare, and into many foolish and hurtful lusts, which drown men in destruction and perdition.

O Timothy, take good care of that which is given to you, turning away from the wrong and foolish talk and arguments of that knowledge which is falsely so named;