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nutation

[noo-tey-shuh n, nyoo-]
noun
  1. an act or instance of nodding one's head, especially involuntarily or spasmodically.
  2. Botany. spontaneous movements of plant parts during growth.
  3. Astronomy. the periodic oscillation observed in the precession of the earth's axis and the precession of the equinoxes.
  4. Mechanics. the variation of the inclination of the axis of a gyroscope to the vertical.

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
Related formsnu·ta·tion·al, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for nutation

Historical Examples of nutation

British Dictionary definitions for nutation

nutation

noun
  1. astronomy a periodic variation in the precession of the earth's axis causing the earth's poles to oscillate about their mean position
  2. physics a periodic variation in the uniform precession of the axis of any spinning body, such as a gyroscope, about the horizontal
  3. Also called: circumnutation the spiral growth of a shoot, tendril, or similar plant organ, caused by variation in the growth rate in different parts
  4. the act or an instance of nodding the head
Derived Formsnutational, adjective

Word Origin for nutation

C17: from Latin nutātiō, from nūtāre to nod
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 nutation
n.

1610s, "action of nodding," from Latin nutationem (nominative nutatio), noun of action from past participle stem of nutare "to nod," from PIE *neu- "to nod" (see numinous). Astronomical use is from 1715. Related: Nutational.

Online Etymology Dictionary, © 2010 Douglas Harper
nutation in Medicine

nutation

[nōō-tā′shən]
n.
  1. The act of nodding the head, especially involuntarily.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
nutation in Science

nutation

[nōō-tā′shən]
  1. 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.
  2. A slight curving or circular movement in a stem, as of a twining plant, caused by irregular growth rates of different parts.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.