English Dictionary
◊ DIURNAL
diurnal
adj 1: (biology) belonging to or active during the day; "diurnal
animals are active during the day"; "diurnal flowers
are open during the day and closed at night" [ant: {nocturnal}]
2: having a daily cycle or occurring every day; "diurnal
rhythms"; "diurnal rotation of the heavens"; "the diurnal
slumber of bats"