Source : Webster's Revised Unabridged Dictionary (1913)

Nightjar \Night"jar`\, n.
   A goatsucker, esp. the European species. See Illust. of
   {Goatsucker}.

Source : WordNet®

nightjar
     n : mainly crepuscular or nocturnal nonpasserine birds with
         mottled grayish-brown plumage and large eyes; feed on
         insects [syn: {goatsucker}, {caprimulgid}]