[ noh-mon ]
See synonyms for gnomon on
  1. the raised part of a sundial that casts the shadow; a style.

  2. an early astronomical instrument consisting of a vertical shaft, column, or the like, for determining the altitude of the sun or the latitude of a position by measuring the length of its shadow cast at noon.

  1. Geometry. (formerly) the part of a parallelogram that remains after a similar parallelogram has been taken away from one of its corners.

Origin of gnomon

1540–50; <Latin gnōmōn pin of a sundial <Greek gnṓmōn literally, interpreter, discerner

Words Nearby gnomon Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use gnomon in a sentence

  • But I landed in the dark chamber of a gnomon, waist-deep in loose wheat.

    Pharaoh's Broker | Ellsworth Douglass
  • I mounted the only unsealed gnomon and shouted down into its cavernous depths.

    Pharaoh's Broker | Ellsworth Douglass
  • A gnomon or pin erected so as to throw its traveling shadow across a graduated arc constitutes a dial.

    The Old Furniture Book | N. Hudson Moore
  • A figure in the shape of a gnomon put round two sides of a square makes it into a larger square.

    Archimedes | Thomas Little Heath
  • And the given absolute magnitude to which it is equal is the rectangle beneath the unequal segments, without gnomon.

    William Oughtred | Florian Cajori

British Dictionary definitions for gnomon


/ (ˈnəʊmɒn) /

  1. the stationary arm that projects the shadow on a sundial

  2. a geometric figure remaining after a parallelogram has been removed from one corner of a larger parallelogram

Origin of gnomon

C16: from Latin, from Greek: interpreter, from gignōskein to know

Derived forms of gnomon

  • gnomonic, adjective
  • gnomonically, 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