NOCTURNAL

[noc.tur.nal] adj [ME, fr. MF or LL; MF, fr. LL nocturnalis, fr. L nocturnus of night, nocturnal, fr. noct-, nox night] (15c) 1: of, relating to, or occurring in the night "a ~ journey"

2: active at night "a ~ predator" -- noc.tur.nal.ly adv