precession
NounOpen English WordNet
Noun (2)
- the motion of a spinning body (as a top) in which it wobbles so that the axis of rotation sweeps out a coneType of motion
- the act of preceding in time or order or rank (as in a ceremony)Synonyms: precedenceprecedencyType of activity
What does it mean? Question 1 of today’s quiz
Webster's Dictionary (1913)
Origin: L. praecedere, praecessum, to go before: cf. F. précession. See Precede.
The act of going before, or forward.
Lunisolar precession. Astronomy See under Lunisolar. — Planetary precession, that part of the precession of the equinoxes which depends on the action of the planets alone. — Precession of the equinoxes Astronomy, the slow backward motion of the equinoctial points along the ecliptic, at the rate of 50.2″ annually, caused by the action of the sun, moon, and planets, upon the protuberant matter about the earth's equator, in connection with its diurnal rotation; — so called because either equinox, owing to its westerly motion, comes to the meridian sooner each day than the point it would have occupied without the motion of precession, and thus precedes that point continually with reference to the time of transit and motion.
Webster’s Revised Unabridged Dictionary (1913), from GCIDE 0.54