any of several thick-billed, crepuscular or nocturnal herons of the genus Nycticorax and related genera, as N. nycticorax(black-crowned night heron) of the Old and New Worlds, and Nyctanassa violacea(yellow-crowned night heron) of America.
Origin
1775-85
British Dictionary definitions for night heron
night heron
noun
1.
any nocturnal heron of the genus Nycticorax and related genera, having short legs and neck, a heavy body, and a short heavy bill