nutation
Americannoun
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an act or instance of nodding one's head, especially involuntarily or spasmodically.
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Botany. spontaneous movements of plant parts during growth.
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Astronomy. the periodic oscillation observed in the precession of the earth's axis and the precession of the equinoxes.
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Mechanics. the variation of the inclination of the axis of a gyroscope to the vertical.
noun
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astronomy a periodic variation in the precession of the earth's axis causing the earth's poles to oscillate about their mean position
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physics a periodic variation in the uniform precession of the axis of any spinning body, such as a gyroscope, about the horizontal
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Also called: circumnutation. the spiral growth of a shoot, tendril, or similar plant organ, caused by variation in the growth rate in different parts
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the act or an instance of nodding the head
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A small, cyclic variation of the Earth's axis of rotation with a period of 18.6 years, caused by tidal forces (mostly due to the gravity of the Moon). Nutation is a small and relatively rapid oscillation of the axis superimposed on the larger and much slower oscillation known as precession. Although discovered in 1728 by the British astronomer James Bradley (1693–1762), nutation was not explained until two decades later.
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A slight curving or circular movement in a stem, as of a twining plant, caused by irregular growth rates of different parts.
Other Word Forms
Etymology
Origin of nutation
1605–15; < Latin nūtātiōn- (stem of nūtātiō ), equivalent to nūtāt ( us ) (past participle of nūtāre to nod repeatedly; nū- nod + -tā- frequentative suffix + -tus past participle ending) + -iōn- -ion; cf. numen
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
But how many people are aware that pizzlesprung is a Kentucky word to describe the weary, or that nutation is the wobble in the earth's axis caused by the pull of the moon?
From Time Magazine Archive
Even the tides and precession of the equinoxes and Bradley's nutation were accounted for and explained.
From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck
In seven genera of twining plants* the hooking, or as it has been called by Sachs, the nutation of the tip, is mainly due to an exaggerated form of circumnutation.
From The Power of Movement in Plants by Darwin, Charles
Why did he not continue in the same spot, except for the slow change caused by the nutation or nodding of Venus?
From A Trip to Venus by Munro, John
This led him to the discovery of the “aberration” of light and of nutation.
From History of Astronomy by Forbes, George
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
