D defs.my
Entry 2 senses Webster, 1913

Diurnation

· Di·ur·na·tion · IPA
01 n. Continuance during the day.
  1. 1.
    Continuance during the day.[Obs.]
  2. 2.
    The condition of sleeping or becoming dormant by day, as is the case of the bats.(Zool.)