Definition of diurnal

diurnal Adjective Happening or occurring during daylight, or primarily active during that time.
diurnal Adjective Said of a flower open, or releasing its perfume during daylight hours, but not at night.
diurnal Adjective Having a daily cycle that is completed every 24 hours, usually referring to tasks, processes, tides, or sunrise to sunset.
diurnal Adjective Done once every day; daily, quotidian.
diurnal Adjective Published daily.
diurnal Noun A flower that opens only in the day.
diurnal Noun A book containing canonical offices performed during the day, hence not matins.
diurnal Noun A diary or journal.
diurnal Noun A daily news publication.