Among older people, dehydration is one of the most common hazards of hot, humid weather. See what you can save with the AARP Auto Buying Program. Recent studies have found that even mild dehydration comes with big consequences â from altered mood and impaired memory to headaches and constipation.
diurnal - of or 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; diurnal and nocturnal offices. 2. diurnal - having a daily cycle or occurring every day; diurnal rotation of the heavens.
Princeton's WordNet (3.00 / 1 vote) Rate this definition: day, twenty-four hours, twenty-four hour period, 24-hour interval, solar day, mean solar day (noun) time for Earth to make a complete rotation on its axis two days later they left; they put on two performances every day; there are 30,000 passengers per day day (noun)