Noun

(-)

A sphere shaped droplet of molten lava ejected from a volcanic eruption which falls to earth while still at least partially molten, ranging in size from 2 to 64 millimeters.

* {{quote-news, year=2007, date=May 8, author=Henry Fountain, title=It’s Still Dark Out, So Why Are the Birds Singing Away?, work=New York Times citation

, passage=They also found rounded granules that are probably accretionary lapilli — volcanic hailstones, formed as material gathers in the air. }}