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gnomon

Line breaks: gnomon
Pronunciation: /ˈnəʊmɒn
 
/

Definition of gnomon in English:

noun

1The projecting piece on a sundial that shows the time by the position of its shadow.
Example sentences
  • The problem is that the gardeners have been caught on the gnomon of their own sundial.
  • He also probably introduced the gnomon (a perpendicular sun-dial) into Greece and erected one in Sparta.
  • He placed a pole perfectly upright in the ground to make a simple sundial, or gnomon.
1.1 Astronomy A structure, especially a column, used in observing the sun’s meridian altitude.
Example sentences
  • The simplest astronomical instruments was the gnomon, nothing other than a stick which was erected and the length of its shadow measured.
  • He is also said to have constructed a armillary sphere, a water clock, and a bronze gnomon, a pointer whose shadow gives the time of mid-day.
  • Pergolas, open steel stairs, lattices and wooden blinds all act as shadow-casters and gnomons.
2 Geometry The part of a parallelogram left when a similar parallelogram has been taken from its corner.
Example sentences
  • Revolve the gnomon about its vertex and it can draw a circle; combine two gnomons and they form a square.
  • When the gnomon is turned up, it can measure height; when it is turned over, it can measure depth and when it lies horizontally it can measure distance.

Origin

mid 16th century: via Latin from Greek gnōmōn 'indicator, carpenter's square' (related to gignōskein 'know').

Derivatives

gnomonic

1
Pronunciation: /-ˈmɒnɪk/
adjective
Example sentences
  • Loxodromes appear as straight lines on the Mercator projection, while orthodromes appear as straight lines on the gnomonic projection.
  • The videos were projected onto two screens built to replicate the gnomonic and ‘Robinson projections’ of representing the globe on a two dimensional surface.
  • A gnomonic image, meanwhile, tends to make the surface appear flat, and is used by navigators and aviators in determining the shortest distance between two points.

Words that rhyme with gnomon

Jomon

Definition of gnomon in:

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