(topology) A topological space which is a product of two circles. / A ring-shaped object, especially a large ring-shaped chamber used in physical research.

(topology) The topological space that is a Cartesian product of the two-dimensional disk and the circle.

(anatomy) A protrusion on the lateral wall of the nasopharynx marking the pharyngeal end of the cartilaginous part of the Eustachian tube.

(combinatorics) An array of symbols from an alphabet (often just 0 and 1) that contains every m-by-n matrix exactly once.

plural of torus