lapilli

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 6 millimeters.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.