to hide something by covering it over, usually by burying it in the ground
This verb pictures a very concrete action: you put a thing where it cannot be seen by covering it up, most often by burying it in the earth, the sand, or a wall. Moses hides the body of the Egyptian in the sand; Jacob buries the household idols under a tree; Achan buries the stolen goods in the floor of his tent. The word is not the general idea of getting out of view. It is the specific act of tucking something away so it stays out of reach.
That same picture powers its most frequent use in the Psalms, where enemies hide a net, a snare, or a pit. The point is ambush: the trap is set out of sight so the victim walks into it without warning. When you read that someone has hidden a snare, the danger is not that the trap is merely stored somewhere but that it lies concealed in the path.
From there the word stretches a little further. A person can be hidden away (Rahab hides the spies under stalks of flax), a person can hide himself in the dust to escape terror, and a guilty person can bury his sin in his own heart so no one sees it. In every case the core stays the same: something is covered over and kept from sight.
The book of Proverbs even turns it into a joke. The lazy man buries his hand in the dish and is too worn out to lift it back to his mouth. The humor works because the ordinary meaning of the word is so physical: he has plunged his hand in and left it there, as good as buried.