an iris, Iris tectorum, of China and Japan, having frilled, violet or white flowers.
adjective 1. having no roof. 2. without the shelter of a house: roofless refugees.
noun 1. the outline of a rooftop.
- Roof of fourth ventricle
roof of fourth ventricle n. The roof of the fourth ventricle formed by the inferior and the superior medullary vela.
- Roof of tympanum
roof of tympanum n. The roof of the middle ear, formed by the thinned anterior surface of the petrous portion of the temporal bone.