This shows grade level based on the word's complexity.
planetesimal
[ plan-i-tes-uh-muhl ]
/ ˌplæn ɪˈtɛs ə məl /
Save This Word!
This shows grade level based on the word's complexity.
noun
one of the small celestial bodies that, according to one theory (planetesimal hypothesis ), were fused together to form the planets of the solar system.
adjective
of or relating to a planetesimal or planetesimals.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?
Origin of planetesimal
First recorded in 1900–05; planet + (infinit)esimal
Words nearby planetesimal
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use planetesimal in a sentence
Scientific definitions for planetesimal
planetesimal
[ plăn′ĭ-tĕs′ə-məl ]
Any of innumerable small bodies of accreted gas and dust thought to have orbited the Sun during the formation of the planets.♦ The theory that explains the formation of the solar system in terms of the aggregation of such bodies is known as the planetesimal hypothesis. According to this theory, first proposed in 1900, the planetesimals formed within a spiral disk of dust and gas surrounding a central nucleus. Their gravitational attraction eventually caused the planetesimals to coalesce into protoplanetary disks from which larger objects such as planets, asteroids, and satellites were formed, while the nucleus coalesced into the Sun.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.