Meaning of DIAGONAL in English

DIAGONAL

[ dʌɪ'ag(ə)n(ə)l ]

■ adjective denoting a straight line joining opposite corners of a rectangle, square, or other figure.

↘(of a line) straight and at an angle; slanting.

↘ Mathematics denoting a matrix with non-zero elements only on the ~ running from the upper left to the lower right.

■ noun a ~ line.

Derivatives

~ly adverb

Origin

C16: from L. ~is , from Gk diagōnios 'from angle to angle', from dia 'through' + gōnia 'angle'.

Concise Oxford English vocab.      Сжатый оксфордский словарь английского языка.