- 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.
- c. 1604–1605, William Shakespeare, “All’s VVell, that Ends VVell”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act II, scene v]:
- Ere twice the horses of the sun shall bring / Their fiery torcher his diurnal ring.
- (botany) Said of a flower open, or releasing its perfume during daylight hours, but not at night.
- Having a daily cycle that is completed every 24 hours, usually referring to tasks, processes, tides, or sunrise to sunset; circadian.
- (uncommon) Done once every day; daily, quotidian.
- (archaic) Published daily.
- (having a daily cycle) circadian (biology)
diurnal (plural diurnals)
- A flower that opens only in the day.
- (Catholicism) A book containing canonical offices performed during the day, hence not matins.
- (archaic) A diary or journal.
- (archaic) A daily news publication.