One of the mysteries of the English language finally explained.
1Of or during the day.
active during the day, non-nocturnalView synonyms
- ‘I'll get maybe three, four good diurnal emissions off per day, I reckon.’
- ‘It's now 6am, which is the equivalent of 6pm for all of those conservative diurnal types.’
- ‘A feature shared by many clock gene transcripts is that their abundance is subject to circadian and diurnal oscillation.’
- ‘When I was first married I was practically nocturnal, and my wife was diurnal.’
- ‘The mercury levels now seem to have changed with diurnal temperature difference narrowing down.’
- 1.1Zoology (of animals) active in the daytime.
- ‘Finally, group living often provides diurnal rodents with better predator defenses.’
- ‘They are diurnal herbivores, hiding in reef crevices during nighttime and browsing over reefs to feed during the day.’
- ‘The male provides no direct parental care except to protect the eggs against diurnal fish predators.’
- ‘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.’
- 1.2Botany (of flowers) open only during the day.
- ‘Ammonium concentrations in roots and leaves undergo diurnal changes.’
- ‘NRA showed important diurnal changes in leaves and roots tissues.’
- ‘The sample traces (a, b) are representative of the diurnal pattern of leaf extension rate for each species.’
- ‘There are only marginal changes in phosphorylated intermediates in the diurnal time-frame or during tuber development.’
- ‘Are diurnal changes of turgor and leaf growth correlated with each other?’
2Daily; of each day.‘diurnal rhythms’
daily, everyday, day-to-day, quotidianView synonyms
- ‘Her diurnal ritual of hurriedly brushing her hair before the mirror expands to one of self-admiration.’
- ‘The absence of a diurnal rhythm would be a significant difference between growth control in roots and dicot leaves.’
- ‘For the most part, this diurnal ritual occurs around 6: 30 a.m.’
- ‘The diurnal rhythm of cortisol secretion in the horse peaks at approximately 0600 h and is least at approximately 1800 h.’
- ‘Universal, reliable and even human-made light, completely independent of diurnal rhythm, has abolished the shamanist aspects of our calling.’
- ‘What I needed for recovery was a long period of rest in a comfortable setting with a familiar diurnal schedule.’
- ‘They have their own diurnal cycles, pegged to alien time-frames.’
- ‘Too late for conventional diurnal rhythms; too early for genuine nocturnal ones.’
- ‘This apparently inefficient system gives us the ability to deal with the natural variability of the diurnal rhythms of light and temperature.’
- ‘Today FM, for example, operates to a finely calibrated diurnal rhythm, carefully tuned to the mood of its audience.’
- ‘The APR of maize and Arabidopsis thaliana follows a diurnal rhythm with maximum activity during the light period.’
- ‘Experiments were performed always at the same time of the day, to avoid interference with diurnal rhythms.’
- ‘Moreover, while minor amino acids show marked diurnal rhythms, their contents fluctuate in a co-ordinated manner.’
- ‘The transporters show different expression patterns in response to diurnal rhythm.’
- ‘This impulse to explore the diurnal is shared by cinema which similarly took everyday objects and put them on exhibit as a form of ‘art’.’
- 2.1Astronomy Of or resulting from the daily rotation of the earth.
- ‘Magnetism, in other words, caused the Earth's Copernican diurnal rotation.’
- ‘Right ascension makes it easy to use the apparent diurnal rotation of the celestial sphere as a means to telling time.’
- ‘In poetic form, Aryabhata stated that the earth's diurnal rotation on its axis produced the daily rising and setting of planets and stars.’
- ‘What mattered was the planet's diurnal position relative to the horizon - whether it was rising in the east or culminating overhead.’
- ‘He explained eclipses, solstices and equinoxes, announced the sphericity of the earth and its diurnal revolution on its axis.’
Late Middle English (as a term in astronomy): from late Latin diurnalis, from Latin diurnus ‘daily’, from dies ‘day’.
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