diurnal

From Latin diurnālis, from diēs (“day”). Cognate with journal.

• (UK) IPA^(key): [daɪˈɜːnəɫ]
• (US) IPA^(key): /daɪˈɝ.nəl/

• Audio (US)

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• Audio (AU)

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  Rhymes: -ɜː(r)nəl

diurnal (comparative more diurnal, superlative most diurnal)

1. Happening or occurring during daylight, or primarily active during that time.

   Most birds are diurnal.

   • 1972, Laurence Monroe Klauber, Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind, Volume 1

     However, in general, lizards are more diurnal than rattlers, which may be one of the reasons why young rattlers are more diurnal than adults.

   • Shakespeare

     Ere twice the horses of the sun shall bring / Their fiery torcher his diurnal ring.

2. (botany) Said of a flower open, or releasing its perfume during daylight hours, but not at night.
3. Having a daily cycle that is completed every 24 hours, usually referring to tasks, processes, tides, or sunrise to sunset; circadian.
4. (uncommon) Done once every day; daily, quotidian.
5. (archaic) Published daily.

• For quotations of use of this term, see Citations:diurnal.

• (having a daily cycle): circadian (biology)

• (happening or active during the day): nocturnal, nightly
• (active or open during the day): nocturnal

• (active or open during the day): crepuscular

diurnal (plural diurnals)

1. A flower that opens only in the day.
2. (Catholicism) A book containing canonical offices performed during the day, hence not matins.
3. (archaic) A diary or journal.
   • 1663, Samuel Butler, Hudibras, part 1, canto 2:

     He was by birth, some authors write, / A Russian, some a Muscovite, / And 'mong the Cossacks had been bred, / Of whom we in diurnals read.

4. (archaic) A daily news publication.