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.
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.
- di·ag·o·nal·ly, adverb
- non·di·ag·o·nal, adjective, noun
- non·di·ag·o·nal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use diagonal in a sentence
The diagonal-thinking capability that balances short-term necessity with longer-term opportunity.With many employees wary, company leaders prepare their return-to-office coronavirus vaccine policies | Jessica Davies | January 18, 2021 | Digiday
These pairs are spaced apart so the grid looks like a checkerboard, with diagonals crossing every other square.The Curious Strength of a Sea Sponge’s Glass Skeleton | Elena Renken | January 11, 2021 | Quanta Magazine
The skeleton of the Venus’ flower basket, however, has pairs of diagonals running in both directions rather than the single diagonals crisscrossing a typical truss.The Curious Strength of a Sea Sponge’s Glass Skeleton | Elena Renken | January 11, 2021 | Quanta Magazine
In so doing, it drops below the diagonal line, one of the only counties to do so.Texas has managed the near-impossible: Its presidential election lawsuit just got worse | Philip Bump | December 11, 2020 | Washington Post
It reduces the turning radius of the vehicle, which is handy in everyday situations, but it also allows the truck to drive on a sideways diagonal path, like a crab.The 2022 GMC electric Hummer looks a lot different than you might expect | Stan Horaczek | October 21, 2020 | Popular-Science
I was waiting for something to happen and it was like an explosion, everything shot diagonally left across the track.Prince Harry at Silverstone Grand Prix To See Lewis Hamilton Win | Tom Sykes | July 7, 2014 | THE DAILY BEAST
We accidentally put a highway to nowhere cutting diagonally across our island.SimCity Is Smarter Than You (Even If You’re an Urban Planner) | Josh Dzieza | February 26, 2013 | THE DAILY BEAST
Dressed in a black suit, Roubini was seated diagonally across from Osborne at a table in the corner of the room.
Three model train tracks run diagonally across the broken glass.
Panels may be woven either length-wise (step 8), crosswise (step 8), diagonally across the mat (step 4), or in zigzags (step 3).Philippine Mats | Hugo H. Miller
I secured a used broom, the longer and newer the better, and cut the straws off diagonally across the sweeping edge.The Boy Mechanic, Book 2 | Various
The cloud passed across the straits diagonally to the south-west.Left on Labrador | Charles Asbury Stephens
The last half-league of the way is very steep, and leads to the ridge of a chain of hillocks running diagonally across the valley.
Following the direction of his eyes, Whiteside saw two deep furrows running diagonally across the grip.The Daffodil Mystery | Edgar Wallace
British Dictionary definitions for diagonal
maths connecting any two vertices that in a polygon are not adjacent and in a polyhedron are not in the same face
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
- diagonally, adverb
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
Scientific definitions for diagonal
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.