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diurnal

adjective

of or relating to a day or each day; daily.
of or belonging to the daytime (opposed to nocturnal).
Botany. showing a periodic alteration of condition with day and night, as certain flowers that open by day and close by night.
active by day, as certain birds and insects (opposed to nocturnal).

noun

Liturgy. a service book containing offices for the daily hours of prayer.
Archaic. a diary.
Archaic. a newspaper, especially a daily one.

adjective

happening during the day or daily
(of flowers) open during the day and closed at night
(of animals) active during the dayCompare nocturnal

noun

a service book containing all the canonical hours except matins

adj.

late 14c., from Late Latin diurnalis “daily,” from Latin dies “day” + -urnus, an adjectival suffix denoting time (cf. hibernus “wintery”). Dies “day” is from PIE root *dyeu- “to shine” (cf. Sanskrit diva “by day,” Welsh diw, Breton deiz “day;” Armenian tiw; Lithuanian diena; Old Church Slavonic dini, Polish dzień, Russian den), literally “to shine” (cf. Greek delos “clear;” Latin deus, Sanskrit deva “god,” literally “shining one;” Avestan dava- “spirit, demon;” Lithuanian devas, Old Norse tivar “gods;” Old English Tig, genitive Tiwes, see Tuesday).

adj.

Having a 24-hour period or cycle; daily.
Occurring or active during the daytime rather than at night.

1. Occurring once in a 24-hour period; daily.
2. Having a 24-hour cycle. The movement of stars and other celestial objects across the sky are diurnal.
Most active during the daytime. Many animals, including the apes, are diurnal.
Having leaves or flowers that open in daylight and close at night. The morning glory and crocus are diurnal. Compare nocturnal.