Definition of diurnal
- a. - Relating to the daytime; belonging to the period of
daylight, distinguished from the night; -- opposed to nocturnal; as,
diurnal heat; diurnal hours.
- a. - 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.
- a. - Opening during the day, and closing at night; -- said of
flowers or leaves.
- a. - Active by day; -- applied especially to the eagles and
hawks among raptorial birds, and to butterflies (Diurna) among insects.
- a. - A daybook; a journal.
- a. - A small volume containing the daily service for the
"little hours," viz., prime, tierce, sext, nones, vespers, and
compline.
- a. - A diurnal bird or insect.