diagonal

 
Pronunciation: /dʌɪˈag(ə)n(ə)l/

adjective

  • (of a straight line) joining two opposite corners of a square, rectangle, or other straight-sided shape.
  • (of a line) straight and at an angle; slanting: a tie with diagonal stripes

noun

  • a straight line joining two opposite corners of a square, rectangle, or other straight-sided shape.
  • Mathematics the set of elements of a matrix that lie on a line joining two opposite corners.
  • a slanting straight line: the bars of light made diagonals across the entrance tiles can be laid on the diagonal
  • Chess a slanting row of squares whose colour is the same.

Origin:

mid 16th century: from Latin diagonalis, from Greek diagōnios 'from angle to angle', from dia 'through' + gōnia 'angle'