| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024pre•ces•sion (prē sesh′ən),USA pronunciation n. - the act or fact of preceding;
precedence. - Metallurgy, Mechanics[Mech.]the motion of the rotation axis of a rigid body, as a spinning top, when a disturbing torque is applied while the body is rotating such that the rotation axis describes a cone, with the vertical through the vertex of the body as axis of the cone, and the motion of the rotating body is perpendicular to the direction of the torque.
- Astronomy
- the slow, conical motion of the earth's axis of rotation, caused by the gravitational attraction of the sun and moon, and, to a smaller extent, of the planets, on the equatorial bulge of the earth.
- See precession of the equinoxes.
- Late Latin praecessiōn- (stem of praecessiō) a going before, advance, equivalent. to Latin praecess(us) (past participle of praecēdere to precede) + -iōn- -ion; see cession
- 1300–50
Collins Concise English Dictionary © HarperCollins Publishers:: precession /prɪˈsɛʃən/ n - the act of preceding
- See precession of the equinoxes
- the motion of a spinning body, such as a top, gyroscope, or planet, in which it wobbles so that the axis of rotation sweeps out a cone
Etymology: 16th Century: from Late Latin praecessiō a going in advance, from Latin praecēdere to precedepreˈcessional adj preˈcessionally adv |