Dictionary definition · diagonal
noun
- (geometry) a straight line connecting any two vertices of a polygon that are not adjacent
- a line or cut across a fabric that is not at right angles to a side of the fabric
- an oblique line of squares of the same color on a checkerboard"the bishop moves on the diagonals"
- (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
- a punctuation mark (‘/’) used to separate related items of information
adjective
- 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"
- having an oblique or slanted direction
Source: Open English WordNet (CC BY 4.0).