Gnomon

Quick meaning: Gnomon is a noun meaning The index of the hour circle of a globe.

Meaning

The index of the hour circle of a globe.

More Meanings

1. (geometry) A plane figure formed by removing a parallelogram from a corner of a larger parallelogram.
2. An object such as a pillar or a rod that is used to tell time by the shadow it casts when the sun shines on it, especially the pointer on a sundial.
3. (mathematics, by extension) A number representing the increment between two figurate numbers (“numbers equal to the numbers of dots in geometric figures formed of dots”).
4. An object such as a pillar used by an observer to calculate the meridian altitude of the sun (that is, the altitude of the sun when it reaches the observer's meridian), for the purpose of determining the observer's latitude.

Example Sentences

[T]he gnomon being the upright, and the shadow the side, the square-root of the sum of the squares is the hypotenuse; […]

Index of a globe, the little style or gnomon, which being fixed on the pole of the globe, and turning round with it, points out the hours upon the hour circle.

If a Parallelogram be divided into four leſſer ones, by two Lines interſecting each other; and one of theſe Parallelograms be retrench'd, or taken away; the other three will make a Gnomon, ordinarily call'd a Square.

Approximate scales can be placed on near-field objects in pictures containing the gnomon by using an ellipse template. The Apollo 16 gnomon […] stands on three legs that, on a hard surface, define a circle 61.7 cm in diameter.

Word Forms

• gnomons

Synonyms for gnomon

Depending on context, synonyms include cock, style.

Related Words

Related dictionary entries include dial, pointer, timekeeper, stud, norman, timepiece.

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