diurnal

Etymology

From Latin diurnālis, from diēs (“day”). Doublet of journal.

adj

1. Happening or occurring during daylight, or primarily active during that time.
   Most birds are diurnal.
   However, in general, lizards are more diurnal than rattlers, which may be one of the reasons why young rattlers are more diurnal than adults. 1972, Laurence Monroe Klauber, Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind, Volume 1
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.

noun

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.
   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. 1663, Samuel Butler, Hudibras, part 1, canto 2
4. (archaic) A daily news publication.