Noah Webster's Dictionary (n.) A single particle of ice falling from a cloud; a frozen raindrop; a pellet of hail.

Multi-Version Concordance Hailstone (1 Occurrence) Isaiah 30:30 Yahweh will cause his glorious voice to be heard, and will show the descent of his arm, with the indignation of his anger, and the flame of a devouring fire, with a blast, storm, and hailstones. (Root in WEB KJV JPS ASV DBY WBS YLT NAS RSV)