from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A surface generated by rotating a tractrix about its asymptote; a tractricoid
- n. Any of various surfaces with constant negative Gaussian curvature.
from the GNU version of the Collaborative International Dictionary of English
- n. The surface of constant negative curvature generated by the revolution of a tractrix. This surface corresponds in non-Euclidian space to the sphere in ordinary space. An important property of the surface is that any figure drawn upon it can be displaced in any way without tearing it or altering in size any of its elements.
from The Century Dictionary and Cyclopedia
- n. A surface of constant negative curvature.
- n. A sphere in non-Euclidean geometry.
- n. The surface generated by the revolution of the tractrix about its asymptote.
pseudo- + sphere (Wiktionary)