Etymology
Advertisement

diurnal (adj.)

late 14c., "daily, happening every day," from Late Latin diurnalis "daily," from Latin dies "day" + -urnus, an adjectival suffix denoting time (compare hibernus "wintery"). Dies "day" is from PIE root *dyeu- "to shine" (source also of Sanskrit diva "by day," Welsh diw, Breton deiz "day;" Armenian tiw; Lithuanian diena; Old Church Slavonic dini, Polish dzień, Russian den).

From early 15c. as "performed in or occupying one day;" 1620s as "of or belonging to the daytime (as distinguished from nocturnal). Related: Diurnally.

updated on September 09, 2018

Advertisement
Advertisement
Definitions of diurnal from WordNet

diurnal (adj.)
of or belonging to or active during the day;
diurnal flowers are open during the day and closed at night
diurnal animals are active during the day
diurnal and nocturnal offices
diurnal (adj.)
having a daily cycle or occurring every day;
diurnal rotation of the heavens
Etymologies are not definitions. From wordnet.princeton.edu, not affiliated with etymonline.