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Webster's Dictionary (1865)

3 entries under this word

Diurnal

Dī-ûr'nal, a.

adjective

a. [Lat. diurnalis, diurnus, from dies, day.]

  1. Relating to the daytime; belonging to the period of daylight, distinguished from the night; as, diurnal heat; diurnal hours; the diurnal butterflies.
  2. Daily; recurring every day; performed in a day; going through its changes in a day; as, a diurnal fever; a diurnal task; diurnal aberration, or diurnal parallax.
  3. Constituting the measure of a day; as, the diurnal revolution of the earth;—as applied to any other planet, constituting the measure of its own day, or one revolution around its own axis.
  4. (Bot.) Opening during the day, and closing at night;—said of flowers or leaves.

Diurnal aberration (Astron.), the aberration of light arising from the combined effect of the earth's rotation and the 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. See MOTION. — Diurnal parallax. See PARALLAX.

Synonyms— See DAILY.

Dī-ûr'nal, n.

noun

[Fr. & Sp. diurnal, a prayer-book. See supra.]

  1. A day-book; a journal. [Obs.] Tatler.
  2. (Ornith.) One of a tribe of raptorial birds, including those which fly by day, and have lateral eyes. Brande.
  3. (Entom.) One of a family of lepidopterous insects which are active only by day. Brande.

Dĭ/ū-tŭr′nal, a.

adjective

a. [From Lat. diuturnus, from diu, a long time, long, an old ablative form of dies, day.] Of long continuance; lasting. Milton.