'Diurnal arc' definitions:
Definition of 'Diurnal arc'
From: GCIDE
- Diurnal \Di*ur"nal\, a. [L. diurnalis, fr. dies day. See Deity, and cf. Journal.]
- 1. Relating to the daytime; belonging to the period of daylight, distinguished from the night; -- opposed to nocturnal; as, diurnal heat; diurnal hours. [1913 Webster]
- 2. Daily; recurring every day; performed in a day; going through its changes in a day; constituting the measure of a day; as, a diurnal fever; a diurnal task; diurnal aberration, or diurnal parallax; the diurnal revolution of the earth. [1913 Webster]
- Ere twice the horses of the sun shall bring Their fiery torcher his diurnal ring. --Shak. [1913 Webster]
- 3. (Bot.) Opening during the day, and closing at night; -- said of flowers or leaves. [1913 Webster]
- 4. (Zool.) Active by day; -- applied especially to the eagles and hawks among raptorial birds, and to butterflies (Diurna) among insects. [1913 Webster]
- Diurnal aberration (Anat.), the aberration of light arising from the effect of the earth's rotation upon the apparent direction of motion of light.
- Diurnal arc, the arc described by the sun during the daytime or while above the horizon; hence, the arc described by the moon or a star from rising to setting.
- Diurnal circle, the apparent circle described by a celestial body in consequence of the earth's rotation.
- Diurnal motion of the earth, the motion of the earth upon its axis which is described in twenty-four hours.
- Diurnal motion of a heavenly body, that apparent motion of the heavenly body which is due to the earth's diurnal motion.
- Diurnal parallax. See under Parallax.
- Diurnal revolution of a planet, the motion of the planet upon its own axis which constitutes one complete revolution.
- Syn: See Daily. [1913 Webster]