Me*rid"i*an, n. [F.
méridien. See Meridian,
1. Midday; noon.
2. Hence: The highest point, as of success,
prosperity, or the like; culmination.
I have touched the highest point of all my
And from that full meridian of my glory
I haste now to my setting.
3. (Astron.) A great circle of the
sphere passing through the poles of the heavens and the zenith of a
given place. It is crossed by the sun at midday.
4. (Geog.) A great circle on the
surface of the earth, passing through the poles and any given place;
also, the half of such a circle included between the poles.
☞ The planes of the geographical and astronomical meridians
coincide. Meridians, on a map or globe, are lines drawn at certain
intervals due north and south, or in the direction of the poles.
Calculated for, or fitted to,
or adapted to, the meridian of,
suited to the local circumstances, capabilities, or special
All other knowledge merely serves the concerns of this
life, and is fitted to the meridian
thereof. Sir M. Hale.
-- First meridian, the meridian from which
longitudes are reckoned. The meridian of Greenwich is the one
commonly employed in calculations of longitude by geographers, and in
actual practice, although in various countries other and different
meridians, chiefly those which pass through the capitals of the
countries, are occasionally used; as, in France, the meridian of
Paris; in the United States, the meridian of Washington, etc. --
Guide meridian (Public Land Survey), a
line, marked by monuments, running North and South through a section
of country between other more carefully established meridians called
principal meridians, used for reference in surveying.
[U.S.] -- Magnetic meridian, a great circle,
passing through the zenith and coinciding in direction with the
magnetic needle, or a line on the earth's surface having the same
direction. -- Meridian circle
(Astron.), an instrument consisting of a telescope
attached to a large graduated circle and so mounted that the
telescope revolves like the transit instrument in a meridian plane.
By it the right ascension and the declination of a star may be
measured in a single observation. -- Meridian
instrument (Astron.), any astronomical
instrument having a telescope that rotates in a meridian plane.
-- Meridian of a globe, or Brass
meridian, a graduated circular ring of brass, in which
the artificial globe is suspended and revolves.
Me*rid"i*an (?), a. [F.
méridien, L. meridianus pertaining to noon, fr.
meridies noon, midday, for older medidies;
medius mid, middle + dies day. See Mid, and
Diurnal.] 1. Being at, or pertaining to,
midday; belonging to, or passing through, the highest point attained
by the sun in his diurnal course. "Meridian hour."
Tables . . . to find the altitude
2. Pertaining to the highest point or
culmination; as, meridian splendor.