a hole: an opening or hollow, whether bored through a surface or worn into the ground
This is a plain, workaday word, and nothing in it tells you how big the hole is. That comes entirely from the setting. A priest bores one in the lid of a chest so worshippers can drop their money in. A prophet is told to dig at one in a wall until it opens into a hidden room. A lover reaches a hand through the one in a door, and the woman inside is undone by it. In each case the word names an opening, and the interest lies in what passes through it.
The other half of its range is a hole in the ground. When soldiers sweep through the countryside, people go into them: the Philistines jeer that the Hebrews are creeping out of the holes they hid in, and Job describes outcasts living in holes of dirt and rock. Animals use them too, the snake a child will one day play beside and the lion that drags its kill home. Hebrew has grander words available, one for a cave you can walk into (מְעָרָה) and one for a beast's proper lair (מְעֹנָה). This one stays small and unglamorous: a gap, not a chamber.
One use sits slightly apart. Zechariah pictures a plague in which people rot while still standing, and their eyes rot in their holes. English says "sockets," and the Hebrew is doing exactly what English does, naming the hollow that holds a thing rather than the thing itself.
It helps to notice what the word is not. It is not a doorway (פֶּתַח), the opening a building is designed around and people walk through on purpose. A hole is what is left when something is bored, broken, dug, or simply never filled in.