An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The direction defined by the → normal to the → reference ellipsoid at the point in question.

→ geodetic; → vertical.

The great circle through the observer's zenith that intersects the horizon at the west and east points. → vertical circle.

→ primary; → vertical.

1) The apparent → direction of → gravity at the point of observation.
2) Being in a position or direction → perpendicular to the → plane of the → horizon. See also → normal.

Vertical, literally "of or at the vertex, directly overhead," from M.Fr. vertical, from L.L. verticalis "overhead," from L. vertex (genitive verticis) "highest point"

Hajin, from haj, variant hac "anything held vertical, erected in the manner of a spear" (Dehxodâ), may be from Proto-Ir. *hac- "to follow;" cf. Av. (+ *ā-) hac- "to stick to;" Mid.Pers. hâz- "to lead, guide;" → associate.

The greater circle on the celestial sphere which passes through → zenith, → nadir, and the star and whose plane is perpendicular to the plane of horizon. Same as → azimuth circle.

→ vertical; → circle.

In computer science, a scaling in which the processing power of the same node/system is increased by increasing/decreasing its resources (CPU, memory, etc.). See also → horizontal scaling.

→ vertical; → scaling.