What is "almucantar"

Almucantar \Al`mu*can"tar\, n. [F. almucantarat, almicantarat, ultimately fr. Ar. al-muqantar[=a]t, pl., fr. qantara to bend, arch.] (Astron.) A small circle of the sphere parallel to the horizon; a circle or parallel of altitude. Two stars which have the same almucantar have the same altitude. See Almacantar.

Almucanter staff, an ancient instrument, having an arc of fifteen degrees, formerly used at sea to take observations of the sun's amplitude at the time of its rising or setting, to find the variation of the compass.

n. (context archaic English) a small circle on the celestial sphere, parallel to the horizon, that is used in astronomy and navigation to show altitude of a star or any other heavenly body.

An almucantar (also spelled almucantarat or almacantara) is a circle on the celestial sphere parallel to the horizon. Two stars that lie on the same almucantar have the same altitude. The term was introduced into European astronomy by monastic astronomer Hermann Contractus of Reichenau, Latinized from the Arabic word ("the almucantar, sundial", plural: ), derived from ("arch, bridge")