nu·ta·tion (no?o-t??sh?n, nyo?o-)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 irregularity in the precessional motion of the earth’s polar axis 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 variation in growth rates of different parts.[Latin n?t?ti?, n?t?ti?n-, from n?t?tus, past participle of n?t?re, frequentative of -nuere, to nod.]nu·ta?tion·al adj.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.nutation (nju??te???n) n1. (Astronomy) astronomy a periodic variation in the precession of the earth’s axis causing the earth’s poles to oscillate about their mean position2. (General Physics) physics a periodic variation in the uniform precession of the axis of any spinning body, such as a gyroscope, about the horizontal3. (Botany) Also called: circumnutation the spiral growth of a shoot, tendril, or similar plant organ, caused by variation in the growth rate in different parts4. the act or an instance of nodding the head[C17: from Latin nut?ti?, from n?t?re to nod] nu?tational adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014nu?ta?tion (nu?te? ??n, nyu-) n. 1. an act or instance of nodding one’s head, esp. involuntarily or spasmodically. 2. spontaneous movements of plant parts during growth. 3. the periodic oscillation observed in the precession of the earth’s axis and of the equinoxes. 4. the variation of the inclination of the axis of a gyroscope to the vertical. [1605?15;