Orientable Surface
orientable surface
[‚ȯr·ē‚en·tə·bəl ′sər·fəs]Orientable Surface
a surface that can be oriented. An orientable surface is the opposite of a nonorientable surface. On a nonorientable surface, for example, a Möbius band, there always exist closed curves such that the orientation of a small neighborhood of a point moving along the curve is reversed when the entire curve is traversed. The projective plane is an important example of a closed nonorientable surface.