gyration
nounUK /dʒaɪ(ə)ˈɹeɪʃ(ə)n/ · US /ˌd͡ʒaɪˈɹeɪʃ(ə)n/
Etymology
From gyre (“to spin around; to gyrate, to whirl; (rare) to make (something) spin or whirl around; to spin, to whirl”) + -ation (suffix indicating actions or processes). Gyre is from Late Middle English giren (“to turn (something) away; to cause (something) to revolve or rotate; to travel in a circle”), from Old French girer (“to turn”), and directly from its etymon Latin gȳrāre, the present active infinitive of gȳrō (“to turn in a circle, rotate; to circle or revolve around”) (from gȳrus (“circle; circular motion; circuit, course”), from Ancient Greek γῦρος (gûros, “a circle, a ring”), from Proto-Indo-European *gew- (“to bend; to curve”)) + -ō (suffix forming regular first-conjugation verbs).
Also, Figuratively The act of turning or whirling, especially around a fixed axis or centre; a circular or spiral motion; rotation.
- Novv that the ayre impelled returnes unto its place in a gyration or vvhirling, is evident from the Atomes or moates in the Sun. For vvhen the Sunne ſo enters a hole or vvindovv, that by its illumination the Atomes or moates become perceptible, if then by our breath the ayre bee gently impelled, it may be perceived that they vvill circularly returne, and in a gyration unto their places againe.1646, Thomas Browne, “Of Bodies Electricall”, in Pseudodoxia Epidemica: […], London: […] T[homas] H[arper] for Edward Dod, […], →OCLC, 2nd book, page 80:
- If Regularity and ſteddineſs accompany Velocity; the motion then leaves not the leaſt track in the ſenſitive. Thus a French Top, the common recreation of School-boys, throvvn from a cord vvhich vvas vvound about it, will ſtand as if it vvere fixt on the floor it lighted; and yet continue in its repeated Gyrations, vvhile the ſenſe diſcovers not the leaſt footſteps of that præcipitate Rotation.1661, Joseph Glanvill, chapter IX, in The Vanity of Dogmatizing: Or Confidence in Opinions. […], London: […] E. C[otes] for Henry Eversden […], →OCLC, pages 80–81:
4 more examples
- If a burning Coal be nimbly moved round in a Circle vvith Gyrations continually repeated, the vvhole Circle vvill appear like fire; the reaſon of vvhich is, that the ſenſation of the Coal in the ſeveral places of that Circle remains impreſt on the Senſorium, until the Coal return again to the ſame place.1704, I[saac] N[ewton], “[The First Book of Opticks. Part II.] Prop[osition] V. Theo[ry] IV. [Exper[iment] X.]”, in Opticks: Or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light. […], London: […] Sam[uel] Smith, and Benj[amin] Walford, printers to the Royal Society, […], →OCLC, page 104:
- His life was a gyration of energetic curiosity; an insatiable whirl of social celebrity.1847, B[enjamin] Disraeli, chapter XIV, in Tancred: Or, The New Crusade. […], volume I, London: Henry Colburn, […], →OCLC, book II, page 291:
- If you question a seaman on the subject, whether mere coaster or circumnavigator, he will tell you that in a snow-storm, because of its constant eddyings and gyrations, frequent trimming of sails is more necessary than in any other gale, and that to steer a straight and steady course under such circumstances is for the time simply impossible.1881 March, “Snow Storm Gales”, in Symon’s Monthly Meteorological Magazine, volume XVI, number CLXXXII, London: Edward Stanford, […], →OCLC, page 59:
- [A] long table of ebony and ivory was unceremoniously cleared of the various objects of art which had been placed on it, and the roulette-wheel was enthroned there instead by the hands of Lady Kenilworth herself, and the little ball was set off on its momentous gyrations.1897, Ouida [pseudonym; Maria Louise Ramé], chapter XIV, in The Massarenes, New York, N.Y.: R. F. Fenno & Company […]; London: Sampson Low, Marston & Co., →OCLC, page 182:
Also, Figuratively, Specifically A rotation around an axis which is not the centre of rotational symmetry; an eccentric or off-centre rotation.
Euclidean geometry
Medicine, Neurology, Neuroscience, Sciences The arrangement of convolutions of gyri in the cerebral cortex of the brain.
- Derived terms
- circumgyration, gyradius, gyrate, gyrational, gyrationally, hypogyration, lævogyration, levogyration, microgyration, oculogyration, radius of gyration
- Related terms
- gyrator, gyratorily, gyratory, gyre, gyrification, gyrified, gyrify, gyrorotary, gyrus