Noun

• S: (n) diagonal ((geometry) a straight line connecting any two vertices of a polygon that are not adjacent)
• S: (n) diagonal, bias (a line or cut across a fabric that is not at right angles to a side of the fabric)
• S: (n) diagonal (an oblique line of squares of the same color on a checkerboard) "the bishop moves on the diagonals"
• S: (n) diagonal ((mathematics) a set of entries in a square matrix running diagonally either from the upper left to lower right entry or running from the upper right to lower left entry)
• S: (n) solidus, slash, virgule, diagonal, stroke, separatrix (a punctuation mark (/) used to separate related items of information)

Adjective

• S: (adj) diagonal (connecting two nonadjacent corners of a plane figure or any two corners of a solid that are not in the same face) "a diagonal line across the page"
• S: (adj) aslant, aslope, diagonal, slanted, slanting, sloped, sloping (having an oblique or slanted direction)