[ee-kwuh-tawr-ee-uh l, -tohr-, ek-wuh-]


of, relating to, or near an equator, especially the equator of the earth.
of, like, or typical of the regions at the earth's equator: equatorial temperatures.


a telescope mounting having two axes of motion, one parallel to the earth's axis and one at right angles to it.
a telescope with such a mounting.


Nearby words

  1. equational verb,
  2. equationally,
  3. equative,
  4. equatively,
  5. equator,
  6. equatorial coordinate system,
  7. equatorial countercurrent,
  8. equatorial current,
  9. equatorial guinea,
  10. equatorial islands

Origin of equatorial

First recorded in 1655–65; equator + -ial

Related forms
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for equatorial

British Dictionary definitions for equatorial



of, like, or existing at or near the equator
astronautics (of a telescope) mounted on the perpendicular axes, one of which is parallel to the earth's axisan equatorial orbit
astronomy of or referring to the celestial equatorequatorial coordinates


an equatorial mounting for a telescope
Derived Formsequatorially, adverb

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 equatorial



1660s, from equator + -al (1).

Online Etymology Dictionary, © 2010 Douglas Harper