diurnal(redirected from diurnal rhythm)
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1. Relating to or occurring in a 24-hour period; daily.
2. Occurring or active during the daytime rather than at night: diurnal animals.
3. Botany Opening during daylight hours and closing at night.
1. A book containing all the offices for the daily canonical hours of prayer except matins.
a. A diary or journal.
b. A daily newspaper.
[Middle English, from Late Latin diurnālis, from Latin diurnus, from diēs, day; see dyeu- in Indo-European roots.]
1. happening during the day or daily
2. (Botany) (of flowers) open during the day and closed at night
3. (Zoology) (of animals) active during the day. Compare nocturnal
(Roman Catholic Church) a service book containing all the canonical hours except matins
[C15: from Late Latin diurnālis, from Latin diurnus, from diēs day]
1. occurring each day; daily.
2. of or belonging to the daytime.
3. occurring in daily cycles: the apparent diurnal motion of celestial bodies.
4. active by day, as certain birds and insects (opposed to nocturnal).
5. opening by day and closing by night, as certain flowers.n.
6. Archaic. diary.
7. Archaic. newspaper.
[1400–50; late Middle English < Latin diurnālis <diurn(us) daily]
1. Occurring in a 24-hour period; daily.
2. Most active during the daytime. Many animals, including the apes, are diurnal. Compare nocturnal.
3. Having leaves or flowers that open in daylight and close at night. The morning glory and crocus are diurnal.
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|Adj.||1.||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"|
nocturnal - belonging to or active during the night; "nocturnal animals are active at night"; "nocturnal plants have flowers that open at night and close by day"
|2.||diurnal - having a daily cycle or occurring every day; "diurnal rotation of the heavens"|