One of several species of insectivorous birds, belonging to Caprimulgus and allied genera, esp. the European species (Caprimulgus Europaeus); -- so called from the mistaken notion that it sucks goats. The European species is also goat-milker, goat owl, goat chaffer, fern owl, night hawk, nightjar, night churr, churr-owl, gnat hawk, and dorhawk .