'Senseless' in the Bible

and I noticed among the naive that is, I discerned among the youths a senseless young man.

Stupidity is the delight of the senseless, but an understanding man walks uprightly.

What is this? A fool has enough money to buy wisdom, but is senseless?

A senseless man striketh hands, becoming surety for his neighbour.

I went by the field belonging to a lazy man, by a vineyard belonging to a senseless person.