ahemeral /eɪˈhɛməɹəl/ adjective1 •Cyclical, with a period not equal to 24 hours.Photostimulation at 22 weeks of age was done with either a normal, hemeral day (14 hours of light; 10 hours of darkness) or a long ahemeral day (14 hours of light; 14 hours of darkness). — 2003
