Glaucous (from Latin glaucus, from Ancient Greek γλαυκός (glaukós) 'blue-green, blue-grey') is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (Larus hyperboreus), glaucous-winged gull (Larus glaucescens), glaucous macaw (Anodorhynchus glaucus), and glaucous tanager (Thraupis glaucocolpa). The term glaucous is also used botanically as an adjective to mean "covered with a greyish, bluish, or whitish waxy coating or bloom that is easily rubbed off" (e.g. glaucous leaves).