diurnal

di·ur·nal  (d-ûrnl)

adj.

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.

n.

1. A book containing all the offices for the daily canonical hours of prayer except matins.

2. Archaic

a. A diary or journal.

b. A daily newspaper.

---

[Middle English, from Late Latin diurnlis, from Latin diurnus, from dis, day; see dyeu- in Indo-European roots.]

---

di·urnal·ly adv.

---

diurnal [die-urn-al]

Adjective

1. happening during the day or daily

2. (of animals) active during the day [Latin diurnus]

---

diurnal  (d-ûrnl)

1.

a. Occurring once in a 24-hour period; daily.

b. Having a 24-hour cycle. The movement of stars and other celestial objects across the sky are diurnal.

2. Most active during the daytime. Many animals, including the apes, are diurnal.

3. Having leaves or flowers that open in daylight and close at night. The morning glory and crocus are diurnal. Compare nocturnal.

Thesaurus

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" biological science, biology - the science that studies living organisms 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" periodic, periodical - happening or recurring at regular intervals; "the periodic appearance of the seventeen-year locust"