a South American night goatsucker (Steatornis caripensis) of a family (Steatornithidae) with only one species; oilbird: the melted fat of the young birds is used for cooking and lighting
See guacharo in American Heritage Dictionary 4
(gwäˈchə-rōˌ)
nounpl.gua·cha·ros
A fruit-eating nocturnal bird (Steatornis caripensis) of South America, whose young have a layer of fat that yields an oil used in cooking and for lighting. Also called oilbird.