A single unit of hail ranging in size from a pea to a grapefruit, or even larger. Layers of ice, similar to an onion represent the accretion of ice as it travels up and down in the drafts of a thunderstorm.

a particle of hail ranging in size from that of a pea to that of a grapefruit

Globule or piece of ice, with a diameter varying between 5 and 50 mm or even more, the fall of which constitutes hail. Hailstones consist almost entirely of transparent ice, or of a series of layers of transparent ice with a thickness of at least 1 mm, alternating with translucent layers.