diagonal

1. not comparablegeometryJoining two nonadjacent vertices (of a polygon or polyhedron).
2. not comparableHaving slanted or oblique lines or markings.
3. not comparableHaving a slanted or oblique direction.

   The visitors' undoing was caused by a diagonal ball from the right which was nodded into the six-yard area by Ian Evatt and finished off by Campbell.

   2011 January 12, Saj Chowdhury, “Liverpool 2 - 1 Liverpool”, in BBC

   Synonyms: aslant, aslope, slanted, slanting, sloped, sloping

4. not comparableOf or related to the cater-corner (diagonally opposite) legs of a quadruped, whether the front left and back right or front right and back left.

plural diagonals

1. geometryA line joining non-adjacent vertices of a polygon.
2. Anything forming or resembling such a line
   1. geometryA line or plane at an oblique angle to another.
   2. fashionA line or cut across a fabric at an oblique angle to its sides.

      Synonyms: bias

   3. uncommonmediaSynonym of slash ⟨/⟩.

      Initial inquiries among professional typists uncover names like slant, slant line, slash, and slash mark. Examination of typing instruction manuals discloses additional names such as diagonal and diagonal mark, and other sources provide the designation oblique.

      1965, Dmitri A. Borgmann, Language on Vacation, page 240

      Synonyms: slash

1. A city and town in Iowa.