a covering: cloth put over the body or over anything, most often clothing.
This is the ordinary word for something spread over a person or a thing to cover it. In practice that usually means clothing, and the Bible treats it as one of life's basics, alongside food. A law protecting a second wife guarantees her food and her covering; another law forbids keeping a poor man's cloak overnight, because it is his only covering and he sleeps in it. When Job pictures the destitute shivering through the night with no covering, he is naming that same essential garment gone missing.
The word leans on the idea of covering more than the plain words for a garment do, so the Bible reaches for it where the covering is doing real work. That lets it stretch. It can name the four-cornered mantle a person literally covers himself with, and it can rise all the way to the sky: God says he clothes the heavens in darkness and makes sackcloth their covering, draping the whole sky in the cloth of mourning.
From the same idea of covering comes the sense of hiding something from view. Job says nothing can hide from God: the world of the dead lies open before him, with no covering to screen it from his sight. And in one difficult scene the phrase "a covering of the eyes" describes not a cloth at all, but a payment that settles a matter and closes people's eyes to it.