[per-uh-hee-lee-uh n, -heel-yuh n]
- the point in the orbit of a planet or comet at which it is nearest to the sun.
Origin of perihelion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the point in its orbit when a planet or comet is nearest the sunCompare aphelion
C17: from New Latin perihēlium, from peri- + Greek hēlios sun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for perihelial
Online Etymology Dictionary, © 2010 Douglas Harper
- The point at which an orbiting object, such as a planet or a comet, is closest to the Sun. Compare aphelion perigee.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.