Welkin is a noun that refers to ‘the sky’ or ‘the heavens above.’
Having its origin in Old English, our word of the day has been around since the 12th century. It may be used in a Biblical sense to refer to the heavens above or it may simply mean ‘the sky.’
When I heard all that racket outside, I expected angles to descend from the welkin. But all I saw coming from the sky was giant, golf-ball sized hail.