IPA: /ˈheɪlstoʊn/
KK: /ˈheɪlstoʊn/
A small, round piece of ice that falls from the sky during a storm.
The hailstones were so large that they damaged the car's roof.
Hailstone → It is formed from "hail" (from Old English *hægel*, meaning hail or frozen rain) and "stone" (from Old English *stan*, meaning rock or stone). The word "hailstone" refers to a small, rounded piece of ice that falls from the sky during a hailstorm, resembling a stone.
Think of 'frozen rain' ('hail') that falls as small 'stones' ('stone') — that's what a hailstone is.