Found 2 items, similar to Prime meridian.
English → English
Definition: prime meridian
n : meridian at zero degree longitude from which east and west
are reckoned (usually the Greenwich longitude in England)
English → English
Definition: Prime meridian
, a. [F., fr. L. primus first, a superl.
corresponding to the compar. prior former. See Prior
, and cf. Prim
, a., Primary
1. First in order of time; original; primeval; primitive;
primary. “Prime forests.”
She was not the prime cause, but I myself. --Milton.
Note: In this sense the word is nearly superseded by
primitive, except in the phrase prime cost.
2. First in rank, degree, dignity, authority, or importance;
as, prime minister. “Prime virtues.”
3. First in excellence; of highest quality; as, prime wheat;
a prime quality of cloth.
4. Early; blooming; being in the first stage. [Poetic]
His starry helm, unbuckled, showed him prime
In manhood where youth ended. --Milton.
5. Lecherous; lustful; lewd. [Obs.] --Shak.
6. Marked or distinguished by a mark (') called a prime mark.
(a) Divisible by no number except itself or unity; as, 7
is a prime number.
(b) Having no common factor; -- used with to; as, 12 is
prime to 25.
[Webster 1913 Suppl.]
Prime and ultimate ratio
. (Math.). See Ultimate
. (Elec.) See under Conductor
(Arith.), a factor which is a prime number.
(Geom.), a figure which can not be divided
into any other figure more simple than itself, as a
triangle, a pyramid, etc.
(Astron.), the meridian from which longitude
is reckoned, as the meridian of Greenwich or Washington.
, the responsible head of a ministry or
executive government; applied particularly to that of
(a) A natural agency applied by man to the production of
power. Especially: Muscular force; the weight and
motion of fluids, as water and air; heat obtained by
chemical combination, and applied to produce changes
in the volume and pressure of steam, air, or other
fluids; and electricity, obtained by chemical action,
and applied to produce alternation of magnetic force.
(b) An engine, or machine, the object of which is to
receive and modify force and motion as supplied by
some natural source, and apply them to drive other
machines; as a water wheel, a water-pressure engine, a
steam engine, a hot-air engine, etc.
(c) Fig.: The original or the most effective force in any
undertaking or work; as, Clarkson was the prime mover
in English antislavery agitation.
(Arith.), a number which is exactly divisible
by no number except itself or unity, as 5, 7, 11.
(Astron.), the vertical circle which passes
through the east and west points of the horizon.
, a dial in which the shadow is
projected on the plane of the prime vertical.
Prime-vertical transit instrument
, a transit instrument the
telescope of which revolves in the plane of the prime
vertical, -- used for observing the transit of stars over