From Longman Dictionary of Contemporary Englishdiurnaldi‧ur‧nal /daɪˈɜːnəl $ -ˈɜːr-/ adjective technical 1 TMChappening or active in the daytime OPP nocturnal2 TMChappening every day
Examples from the Corpus
diurnal• The plains have a wide range of diurnal and annual temperatures.• diurnal animals such as cows• Several studies on digestion of bone by captive owls and diurnal birds of prey have been published.• Many of the diurnal, or daylight-active species are popular aquarium subjects, but there are also several popular nocturnal species.• Two further categories of incisor digestion can be recognized here, covering all the diurnal raptors.• These differences produce corresponding differences in the bone assemblages produced by owls and diurnal raptors.• Many reptiles have a preferred temperature range within internally regulated diurnal rhythms.• Desert areas on Earth often have wide diurnal temperature ranges due to nighttime radiative cooling through very clear skies.• Figure 1 shows the average diurnal variation of ozone and total peroxide in baseline air for January 1992.• In all three cases, the 17-OHCS are elevated and there is no diurnal variation.Origin diurnal (1300-1400) Latin diurnalis, from dies “day” 