- connecting two nonadjacent angles or vertices of a polygon or polyhedron, as a straight line.
- extending from one edge of a solid figure to an opposite edge, as a plane.
- having an oblique direction.
- having oblique lines, ridges, markings, etc.
- a diagonal line or plane.
- a diagonal row, part, pattern, etc.
- Manège. (of a horse at a trot) the foreleg and the hind leg, diagonally opposite, which move forward simultaneously.
- diagonal cloth.
- Mathematics. a set of entries in a square matrix running either from upper left to lower right (main diagonal or principal diagonal) or lower left to upper right (secondary diagonal).
- Chess. one of the oblique lines of squares on a chessboard: He advanced his bishop along the open diagonal.
Origin of diagonal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for diagonal
The young man weaves through clusters of bamboo and cuts a diagonal slash into a tree, positioning a hollow log at the end.The Congo's Forgotten Colonial Getaway
December 18, 2014
A long, diagonal cross from Marcelo saw the ball reach Hulk, who brought it down to his feet from the top of his monumental chest.World Cup 2014 Nail-Biter: Host Country Brazil Defeats Chile on Penalty Kicks
June 28, 2014
Others were paired with sportswear-inspired tops—think a tracksuit zip-up made glam with diagonal decorative panels.Nicolas Ghesquière Presents His Debut Collection for Louis Vuitton
March 5, 2014
I bought wine and I made a wine list and it was the first wine list of its kind: vertical, horizontal, and diagonal.The Queen of the Cookbook
February 23, 2010
Long strips of thin, white paper, about four feet wide, were spread in diagonal lines all over the hall.Red, White, and Muslim
Asma Gull Hasan
February 26, 2009
The jump was diagonal, and made under most difficult circumstances.Two Boys in Wyoming
Edward S. Ellis
Taking this diagonal line as the length, describe another square.Ten Books on Architecture
The sand gully opened towards the sea in a diagonal direction.The Boy Slaves
A door to the left, set in a diagonal wall, gives on to a corridor.Woman on Her Own, False Gods & The Red Robe
Some of the young chaps have their dress-coats made of diagonal.Evening Dress
W. D. Howells
- maths connecting any two vertices that in a polygon are not adjacent and in a polyhedron are not in the same face
- slanting; oblique
- marked with slanting lines or patterns
- maths a diagonal line or plane
- chess any oblique row of squares of the same colour
- cloth marked or woven with slanting lines or patterns
- something put, set, or drawn obliquely
- another name for solidus (def. 1)
- one front leg and the hind leg on the opposite side of a horse, which are on the ground together when the horse is trotting
C16: from Latin diagōnālis, from Greek diagōnios, from dia- + gōnia angle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for diagonal
Online Etymology Dictionary, © 2010 Douglas Harper
- Connecting two nonadjacent corners in a polygon or two nonadjacent corners in a polyhedron that do not lie in the same face.
- A diagonal line segment.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.