Whip-poor-will \Whip"-poor-will`\, n. (Zool.) An American bird ({Antrostomus vociferus}) allied to the nighthawk and goatsucker; -- so called in imitation of the peculiar notes which it utters in the evening. [Written also {whippowil}.] [1913 Webster]
Caprimulgus \Caprimulgus\ n. the type genus of the {Caprimulgidae}, including the {whip-poor-will} ({Caprimulgus vociferus}) and the {chuck-will's-widow} ({Caprimulgus carolinensis}). Syn: genus {Caprimulgus}. [WordNet 1.5 +PJC]
Caprimulgidae \Caprimulgidae\ n. [L. capris goat + mulgere to milk.] 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. Syn: goatsuckers, nightjars, family {Caprimulgidae}. [PJC] 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. --Terence Michael Short (Wild Birds of the Americas)