Atoroidal

In mathematics, there are three definitions for atoroidal as applied to 3-manifolds:

Any algebraically atoroidal 3-manifold is geometrically atoroidal; but the converse is false. However, the mathematical literature often fails to distinguish between them, so one must ascertain any given author's intent.

A 3-manifold that is not atoroidal is called toroidal.