nutation

nu·ta·tion  (n-tshn, ny-)

n.

1. The act or an instance of nodding the head.

2. A wobble in a spinning gyroscope or other rotating body.

3. Astronomy A small periodic motion of the celestial pole of the earth with respect to the pole of the ecliptic.

4. Botany A slight curving or circular movement in a stem, as of a twining plant, caused by irregular growth rates of different parts.

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[Latin ntti, nttin-, from nttus, past participle of ntre, frequentative of -nuere, to nod.]

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nu·tation·al adj.

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nutation  (n-tshn)

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.

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nutation

the periodic oscillation that can be observed in the precession of the earth’s axis and the precession of the equinoxes. See also head. — nutational, adj.

See also: Earth

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the periodic oscillation that can be observed in the precession of the earth’s axis and the precession of the equinoxes. See also 133. EARTH. — nutational, adj.

See also: Astronomy

Thesaurus

Noun

1.

nutation - uncontrolled nodding nod - the act of nodding the head