a widely distributed natural family of nocturnally active birds including the whip-poor-will (Caprimulgus vociferus), the chuck-will's-widow (Caprimulgus carolinensis), and the common nighthawk (Chordeiles minor); -- called popularly the goatsuckers or nightjars. The nighthawks are sometimes active during the day.
The family . . . is alternately known as the nightjars (derived from the "churring" sounds of several species -- "jarring" the night air), or goatsuckers, a nonsense name that should be discontinued as it has its origin in the preposterous myth that the birds sucked the milk of nanny goats until they were dry.