Definition of "planetesimal" [planetesimal]

• Any of innumerable small bodies thought to have orbited the sun during the formation of the planets. (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.

• "The Murchison meteorite, as it is now known, is a fragment of a "planetesimal" or small, solid fragment that condensed out of the solar nebula as the solar system formed."
• "With all those Masonic symbols on its cover, I figured that CULTS, CONSPIRACIES AND SECRET SOCIETIES stood a small chance of being captured by THE LOST SYMBOL's commercial gravity, much as a tiny planetesimal can get pulled into a gas giant's orbit."
• "A handful of components, scraping iron ore from a planetesimal."