Definition of "lapillus" [lapillus]

• A small, solidified fragment of lava. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Nucella lapillus is an intertidal snail commonly found on the rocky coasts of the North Atlantic."
• "Comparison of shell sizes of N. lapillus from 19 sites."
• "Fisher et al. have discovered that between 1915-1922 and 2007, the shell length of N. lapillus at 19 sites around Mount Desert Island, Maine increased by an average of 22.6%."