Diurnal
//daɪˈɜːnəl// adj, noun
adj, noun ·Moderate ·College level
Definitions
Noun
- 1 A flower that opens only in the day.
- 2 A book containing canonical offices performed during the day, hence not matins.
- 3 A diary or journal. archaic
"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 A daily news publication. archaic
Adjective
- 1 Happening or occurring during daylight, or primarily active during that time. not-comparable
"Most birds are diurnal."
- 2 Said of a flower that is open, or releasing its perfume during daylight hours, but not at night. not-comparable
- 3 Having a daily cycle that is completed every 24 hours, usually referring to tasks, processes, tides, or sunrise to sunset; circadian. not-comparable
- 4 Done once every day; daily, quotidian. not-comparable, uncommon
- 5 Published daily. archaic, not-comparable
Adjective
- 1 of or belonging to or active during the day wordnet
- 2 having a daily cycle or occurring every day wordnet
Example
More examples"The net gravitational field at any point on the surface of the earth is the sum of the gravitational fields of all the masses in the universe; hence it displays diurnal and seasonal variations and variations with the phases of the moon and Jupiter; and those variations vary with latitude: if you live far from the poles, you weigh more at night."
Etymology
From Latin diurnālis, from diēs (“day”). Doublet of journal.
Related phrases
More for "diurnal"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.