Azimuthal

Astronomy, Navigation. the arc of the horizon measured clockwise from the south point, in astronomy, or from the north point, in navigation, to the point where a vertical circle through a given heavenly body intersects the horizon.
Surveying, Gunnery. the angle of horizontal deviation, measured clockwise, of a bearing from a standard direction, as from north or south.
Historical Examples

The deviation of a transit-instrument from the plane of the meridian at the horizon; it is also termed the azimuthal error.
The Sailor’s Word-Book William Henry Smyth

I think, to the azimuthal Arch of the Horizon included between the point of sunrise and that of sunset!
Notes and Queries, Number 79, May 3, 1851 Various

noun
(astronomy, nautical) the angular distance usually measured clockwise from the north point of the horizon to the intersection with the horizon of the vertical circle passing through a celestial body Compare altitude (sense 3)
(surveying) the horizontal angle of a bearing clockwise from a standard direction, such as north
n.

“distance of a star from the north or south point of the meridian,” late 14c., from Old French azimut, from Arabic as-sumut “the ways,” plural of as-samt “the way, direction” (see zenith).
azimuth
(āz’ə-məth)
The position of a celestial object along an observer’s horizon. Azimuth is a horizontal angle measured clockwise in degrees from a reference direction, usually the north or south point of the horizon, to the point on the horizon intersected by the object’s line of altitude (a line from the observer’s zenith through the object to the horizon). If north is the reference point (0°), then east has an azimuth of 90°, south is 180°, and so forth through 360°. See more at altazimuth coordinate system.