cir‧ca‧di‧an /sɜːˈkeɪdiən $ sɜːr-/
adjective [only before noun] technical[
Date: 1900-2000;
Language: Latin;
Origin: circa 'around, about' + dies 'day']
relating to a period of 24 hours, used especially when talking about changes in people’s bodies:
the body’s circadian rhythm [TahlilGaran] Dictionary of Contemporary English ▲