- a nocturnal European bird, Caprimulgus europaeus, of the family Caprimulgidae, having a short bill and a wide mouth and feeding on insects captured in the air.
- Also called goatsucker. any other nocturnal or crepuscular bird of the family Caprimulgidae.
- any nocturnal bird of the family Caprimulgidae, esp Caprimulgus europaeus (European nightjar): order Caprimulgiformes. They have a cryptic plumage and large eyes and feed on insects
nocturnal bird, goatsucker, 1620s, from night + jar (v.). So called for the “jarring” sounds made by the male when the female is brooding, which have been described as a “churring trill that seems to change direction as it rises and falls.” An Old English word for it was nihthræfn “night raven.”