diurnal

[ dahy-ur-nl ]

adjective

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

noun

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

diurnal

/ daɪˈɜːnəl /

adjective

1. happening during the day or daily
2. (of flowers) open during the day and closed at night
3. (of animals) active during the day Compare nocturnal

noun

1. a service book containing all the canonical hours except matins

diurnal

/ dī-ûr′nəl /

1. 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.
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.
4. Compare nocturnal

Derived Forms

• diˈurnally, adverb

Other Words From

• di·urnal·ly adverb
• di·urnal·ness noun
• transdi·urnal adjective
• undi·urnal adjective
• undi·urnal·ly adverb

Word History and Origins

Origin of diurnal¹

1400–50; late Middle English < Latin diurnālis, equivalent to diurn ( us ) daily + -ālis -al ¹

Word History and Origins

Origin of diurnal¹

C15: from Late Latin diurnālis, from Latin diurnus, from diēs day

Example Sentences

Wilder’s drama, offering a guided tour of an ordinary town going about its diurnal business, reminds us, through the inescapable shadow of mortality, of what we have in common.

From Los Angeles Times

Yellow-bellied marmots are an excellent study system because they are diurnal, or active during the day, and they have an address.

From Salon

The 12 diurnal tiger beetle species that the researchers included in the study are evidence of this.

From Science Daily

The proteins' diurnal patterns meant that generally speaking, concentrations are typically higher in the mornings and lower in the evenings.

From Science Daily

To assess the impact of simulated microgravity, the research team analysed wrist skin temperature, motor activity, light exposure, and diurnal sleepiness throughout the 90-day protocol.

From Science Daily

Related Words

• constantly
• day-to-day
• everyday
• often
• periodic
• regular
• regularly
• routine