AZIMUTH
azimuth, AZ
(noun) the azimuth of a celestial body is the angle between the vertical plane containing it and the plane of the meridian
Source: WordNet® 3.1
Etymology
Noun
azimuth (plural azimuths)
An arc of the horizon intercepted between the meridian of the place and a vertical circle passing through the center of any object.
The quadrant of an azimuth circle.
Source: Wiktionary
Az"i*muth, n. Etym: [OE. azimut, F. azimut, fr. Ar. as-sum, pl. of
as-samt a way, or perh., a point of the horizon and a circle
extending to it from the zenith, as being the Arabic article: cf. It.
azzimutto, Pg. azimuth, and Ar. samt-al-ra's the vertex of the
heaven. Cf. Zenith.] (Astron. & Geodesy)
(a) The quadrant of an azimuth circle.
(b) An arc of the horizon intercepted between the meridian of the
place and a vertical circle passing through the center of any object;
as, the azimuth of a star; the azimuth or bearing of a line
surveying.
Note: In trigonometrical surveying, it is customary to reckon the
azimuth of a line from the south point of the horizon around by the
west from 0º to 360º. Azimuth circle, or Vertical circle, one of the
great circles of the sphere intersecting each other in the zenith and
nadir, and cutting the horizon at right angles. Hutton.
– Azimuth compass, a compass resembling the mariner's compass, but
having the card divided into degrees instead of rhumbs, and having
vertical sights; used for taking the magnetic azimuth of a heavenly
body, in order to find, by comparison with the true azimuth, the
variation of the needle.
– Azimuth dial, a dial whose stile or gnomon is at right angles to
the plane of the horizon. Hutton.
– Magnetic azimuth, an arc of the horizon, intercepted between the
vertical circle passing through any object and the magnetic meridian.
This is found by observing the object with an azimuth compass.
Source: Webster’s Unabridged Dictionary 1913 Edition