'Hailstone' definitions:

Definition of 'hailstone'

From: WordNet
noun
Small pellet of ice that falls during a hailstorm

Definition of 'Hailstone'

From: GCIDE
  • Hailstone \Hail"stone`\ (-st[=o]n`), n. A single particle of ice falling from a cloud; a frozen raindrop; a pellet of hail. [1913 Webster]