'Foolish' in the Bible

Of laughter I said, 'Foolish!' and of mirth, 'What is this it is doing?'

And who knoweth whether he is wise or foolish? yet he doth rule over all my labour that I have laboured at, and that I have done wisely under the sun! this also is vanity.

Better is a poor and wise youth than an old and foolish king, who hath not known to be warned any more.

The labour of the foolish wearieth him, In that he hath not known to go unto the city.