Word Origin & History
"owl which flies at night," 1593; applied since 1846 (Amer.Eng.) to persons who are up or out late at night. Similarly, night-hawk, used since 1611 of various birds; fig. sense of "one who seeks prey at night, one who stays up late" is from 1818. Cf. Fr. hirondelle de nuit "prostitute," lit. "night-swallow."