From Longman Dictionary of Contemporary Englishdiagonaldi‧ag‧o‧nal /daɪˈæɡənəl/ ●○○ adjective 1 HMHMa diagonal line is straight and joins two opposite corners of a flat shape, usually a square → horizontal, vertical2 CFfollowing a sloping angle diagonal parking spaces —diagonal noun [countable] —diagonally adverb The path goes diagonally across the field.Examples from the Corpus

diagonal• Horizontal or diagonal branches produce more flowering shoots, and therefore more fruit, than vertical ones.• He drew a diagonal line across the page• For a diagonal matrix D having all its diagonal elements different, it follows that C must then also be diagonal.• This equation has a different, but still diagonal, metric tensor.• Patterns include lots of stripes, many of them worked in diagonal or chevron patterns.• On the white-painted wall of the lobby were several outsize representations of lighted cigarettes with a diagonal red line drawn through them.• New dimensions Adding diagonal ribbons creates a new dimension.• Forward seat belts each comprised a two-piece lap strap, fastened by a buckle, and an inertial reel diagonal shoulder strap.• Six to eight diagonal transverse bands lie on the upper half of the body.