diurnal

di·ur·nal

adj \dī-ˈərn-^əl\

Definition of DIURNAL

1

: having a daily cycle <diurnal rhythms>

2

a : of, relating to, or occurring in the daytime <diurnal activity> b : chiefly active during the daytime <diurnal mosquitoes>

—di·ur·nal·ly \-^əl-ē\ adverb