[ per-uh-hee-lee-uh n, -heel-yuh n ]
/ ˌpɛr əˈhi li ən, -ˈhil yən /

noun, plural per·i·he·li·a [per-uh-hee-lee-uh, -heel-yuh] /ˌpɛr əˈhi li ə, -ˈhil yə/. Astronomy.

the point in the orbit of a planet or comet at which it is nearest to the sun.
Compare aphelion.

Origin of perihelion

1660–70; < Greek peri- peri- + hḗli(os) sun + -on neuter noun suffix, on the model of perigee; earlier in the New Latin form perihelium

Related forms

per·i·he·li·al, per·i·he·li·an, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for perihelial


/ (ˌpɛrɪˈhiːlɪən) /

noun plural -lia (-lɪə)

the point in its orbit when a planet or comet is nearest the sunCompare aphelion

Word Origin for perihelion

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

Science definitions for perihelial


[ pĕr′ə-hēlē-ən ]

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.