Definition of diurnal in English:
1Of or during the day.
- When I was first married I was practically nocturnal, and my wife was diurnal.
- It's now 6am, which is the equivalent of 6pm for all of those conservative diurnal types.
- I'll get maybe three, four good diurnal emissions off per day, I reckon.
1.1 Zoology (Of animals) active in the daytime.
- They are diurnal herbivores, hiding in reef crevices during nighttime and browsing over reefs to feed during the day.
- Conversely, subdominant fish were diurnal and occupied large home ranges by day but were generally not observed at night.
- Accipitrids are diurnal birds of prey with broad wings, hooked beaks, strong legs and feet and sharp talons.
2Daily; of each day: diurnal rhythms
More example sentences
- Universal, reliable and even human-made light, completely independent of diurnal rhythm, has abolished the shamanist aspects of our calling.
- This apparently inefficient system gives us the ability to deal with the natural variability of the diurnal rhythms of light and temperature.
- The diurnal rhythm of cortisol secretion in the horse peaks at approximately 0600 h and is least at approximately 1800 h.
2.1 Astronomy Of or resulting from the daily rotation of the earth.
- Magnetism, in other words, caused the Earth's Copernican diurnal rotation.
- In poetic form, Aryabhata stated that the earth's diurnal rotation on its axis produced the daily rising and setting of planets and stars.
- Right ascension makes it easy to use the apparent diurnal rotation of the celestial sphere as a means to telling time.
- Example sentences
- Experimenters have established the use of a time-compensated sun-compass by homing pigeons and diurnally migrating songbirds.
- Males fly readily both diurnally and nocturnally.
- Nocturnal migrants following coasts and diurnally mobile individuals may also be channeled into those peninsular areas.