• WordNet 3.6
    • adj diurnal of or belonging to or active during the day "diurnal animals are active during the day","diurnal flowers are open during the day and closed at night","diurnal and nocturnal offices"
    • adj diurnal having a daily cycle or occurring every day "diurnal rotation of the heavens"
    • ***
Webster's Revised Unabridged Dictionary
    • Diurnal A daybook; a journal.
    • Diurnal (Zoöl) A diurnal bird or insect.
    • Diurnal (R. C. Ch) A small volume containing the daily service for the “little hours,” viz., prime, tierce, sext, nones, vespers, and compline.
    • Diurnal (Zoöl) Active by day; -- applied especially to the eagles and hawks among raptorial birds, and to butterflies (Diurna) among insects.
    • Diurnal 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. "Ere twice the horses of the sun shall bring
      Their fiery torcher his diurnal ring."
    • Diurnal (Bot) Opening during the day, and closing at night; -- said of flowers or leaves.
    • Diurnal Relating to the daytime; belonging to the period of daylight, distinguished from the night; -- opposed to nocturnal; as, diurnal heat; diurnal hours.
    • ***
Century Dictionary and Cyclopedia
    • diurnal Of or belonging to day; pertaining to the daytime; belonging to the period of daylight, as distinguished from the night: opposed to nocturnal: as, diurnal heat; diurnal hours; diurnal habits, as of an animal.
    • diurnal Daily; happening every day: as, a diurnal task.
    • diurnal Performed in or occupying one day; lasting but for one day; ephemeral.
    • diurnal Constituting the measure of a day, either on the earth or one of the other planets: as, the diurnal revolution of the earth, or of Mars or Jupiter.
    • diurnal Characterized by some change or peculiarity which appears and disappears with the daytime, In medicine, being most intense in the daytime: as, a diurnal fever.
    • n diurnal A day-book; a diary; a journal.
    • n diurnal A daily newspaper.
    • n diurnal A Roman Catholic service-book containing the offices for the daily hours of prayer.
    • n diurnal In ornithology, a diurnal bird of prey.
    • n diurnal In entomology, one of the Diurna.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Diurnal dī-ur′nal daily: relating to or performed in a day
    • n Diurnal a service-book containing the day hours, except matins (a night-office): a diary, journal
    • ***


  • William Wordsworth
    “No motion has she now, no force; she neither hears nor sees; rolled around in earth's diurnal course, with rocks, and stones, and trees.”


Webster's Revised Unabridged Dictionary
L. diurnalis, fr. dies, day. See Deity, and cf. Journal


In literature:

But when I read Milton I felt elevated 'above this visible, diurnal sphere.
"Daughters of the Puritans" by Seth Curtis Beach
At ten o'clock the barometer showed a disturbance of the diurnal range.
"Isle o' Dreams" by Frederick F. Moore
This not only obtains in the annual, lunar, and diurnal catenations of animal motions, as explained in Zoonomia, Sect.
"The Temple of Nature; or, the Origin of Society" by Erasmus Darwin
His first impression was soon corrected, and he considered for a time that they might represent a diurnal species of bat.
"Tales of Space and Time" by Herbert George Wells
The diurnal motion of the earth was hardly suspected until a hundred years later.
"Great Men and Famous Women. Vol. 5 of 8" by Various
The excessive diurnal ranges of temperature cause rocks to split and break up.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5" by Various
It has a peculiar kind of hopping gait; and is mainly diurnal, in accordance with which habit its eyes are protected by lashes.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 5" by Various
The earth in its diurnal revolutions travels at the rate of a little more than 1000 miles an hour at the equator.
"Nature's Miracles, Volume 1" by Elisha Gray
As the barometer is constantly oscillating up and down (irrespective of its diurnal oscillation), it has no known fair weather standard.
"The Philosophy of the Weather" by Thomas Belden Butler
Diurnal recoinages are of course out of the question, but the thing is nevertheless both easy and practicable.
"The Arena" by Various

In poetry:

Then every city ward established a guard,
Diurnal and nocturnal:
Militia volunteers, light dragoons, and bombardiers,
With an alderman for colonel.
"The Legend Of St. Sophia Of Kioff" by William Makepeace Thackeray
Oh! that beyond the light diurnal page,
Inscribed on high in monumental gold,
That strain might kindle each succeeding age,
Which thus thy generous indignation roll'd:
"Sheridan" by Thomas Gent
My words and thoughts do both expresse this notion,
That Life hath with the sun a double motion.
The first Is straight, and our diurnall friend;
The other Hid, and doth obliquely bend.
"Colossians iii. 3. "Our Life Is Hid With Christ In God"" by George Herbert
By day the coursers of the sun
Drink of these waters as they run
Their swift diurnal round on high;
By night the constellations glow
Far down the hollow deeps below,
And glimmer in another sky.
"In The Harbour: The Four Lakes Of Madison" by Henry Wadsworth Longfellow
Nothing of tiniest worth
Have I wrought, pondered, planned; no one thing asking blame or
Since the pale corpse-like birth
Of this diurnal unit, bearing blanks in all its rays -
Dullest of dull-hued Days!
"A Commonplace Day" by Thomas Hardy
As day and night succeed alternately;
While the great mantle of the lights of night,
Blanches the chariot of diurnal flames,
As He who governs all,
With everlasting laws,
Puts down the high and raises up the low.
"The Heroic Enthusiasts - Part The Second =Fifth Dialogue=." by Giordano Bruno

In news:

The Importance of Diurnal Variability How valuable are monocular trials in open-angle glaucoma.
For the uninitiated, the osprey ( Pandion haliaetus ), sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey.
Burrowing owls and pygmy owls are more likely to be active during the day or diurnal.
The way we see color today is shaped by events from 35 million years ago, when some nocturnal primates shifted to a diurnal lifestyle, and began to seek out leaves and fruits by day instead of insects and other prey by night.
They are one of the few diurnal owls, active in the day, and the largest owl by weight, with the female adult weighing up to six pounds.
The full study, "Diurnal and Seasonal Mood Vary With Work, Sleep, and Daylength Across Diverse Cultures," is published in the journal Science.

In science:

This approach has been used in [217] to place a bound on the diurnal variation of the anomaly frequency of ∆ω e− a ≤ 1.6 · 10−21me , which limits a particular combination of components of bµ , cµν , dµν Hµν at this level.
Modern tests of Lorentz invariance
The apparent direction of the WIMP flux should be correlated with that of the motion of the sun around the galaxy, and have, in addition to the annual modulation, a diurnal modulation as the laboratory follows the earth rotation on its axis.
Direct search for WIMP dark matter
However, such an experiment would be severely limited by the strong dependence of the Zeeman transition frequency on B , and its diurnal and semi-diurnal variations.
Testing Lorentz Invariance using Zeeman Transitions in Atomic Fountains
Typically, the thermal environment of the experiment must be well regulated for stability of the receiver responsivity and to avoid confusion of diurnal effects from the environment with the daily rotation of the celestial signal.
The Cosmic Microwave Background for Pedestrians: A Review for Particle and Nuclear Physicists
However, solar energy generation tends to be variable due to the diurnal cycle of the solar geometry and clouds.
Storage Size Determination for Grid-Connected Photovoltaic Systems