Precession \Pre*ces"sion\, n. [L. praecedere, praecessum, to go
   before: cf. F. pr['e]cession. See Precede.]
   The act of going before, or forward.
   [1913 Webster]

   Lunisolar precession. (Astron.) 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 (Astron.), the slow backward
      motion of the equinoctial points along the ecliptic, at
      the rate of 50.2[sec] 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.
      [1913 Webster]

Lunisolar \Lu"ni*so"lar\, a. [L. luna moon + E. solar: cf. F.
   lunisolaire.]
   Resulting from the united action, or pertaining to the mutual
   relations, of the sun and moon.
   [1913 Webster]

   Lunisolar precession (Astron.), that portion of the annual
      precession of the equinoxes which depends on the joint
      action of the sun and moon.

   Lunisolar year, a period of time, at the end of which, in
      the Julian calendar, the new and full moons and the
      eclipses recur on the same days of the week and month and
      year as in the previous period. It consists of 532 common
      years, being the least common multiple of the numbers of
      years in the cycle of the sun and the cycle of the moon.
      [1913 Webster]