Main Page | See live article | Alphabetical index In mathematics, reflection (also spelt reflexion) refers to an involutive automorphism of a space which leaves invariant a subspace of codimension 1. Note that this applies to more than just Euclidean geometry. Reflections in affine geometry with respect to a given hyperplane is not unique, for example. Also, an inversion in inversive geometry is considered a reflection by this definition. This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.