from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A one-sided topological surface having no inside or outside. It is depicted in ordinary space by inserting the small open end of a tapered tube through the side of the tube and making it contiguous with the larger open end, although a true Klein bottle would not intersect itself.
After Felix Klein (1849-1925), German mathematician.(American Heritage® Dictionary of the English Language, Fourth Edition)