lapillus definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
noun pl. lapilli
a small fragment of igneous rock, up to the size of a walnut, ejected from a volcano
Origin: Classical Latin diminutive of lapis, stone
lapillus definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
noun pl. la·pil·li
A small, solidified fragment of lava.
Origin: Latin, diminutive of lapis, stone.
lapillus - Science Definition
Plural lapilli lapilli
A small fragment of lava, between 2 and 64 mm in size, blown out from a volcano.