[ dahy-ag-uh-nl, -ag-nl ]
/ daɪˈæg ə nl, -ˈæg nl /



Nearby words

  1. diagnostic specificity,
  2. diagnostic ultrasound,
  3. diagnosticate,
  4. diagnostician,
  5. diagnostics,
  6. diagonal cloth,
  7. diagonal conjugate,
  8. diagonal matrix,
  9. diagonal process,
  10. diagonalize

Origin of diagonal

1535–45; < Latin diagōnālis < Greek diagṓn(ios) from angle to angle (see dia-, -gon) + Latin -ālis -al1

Related formsdi·ag·o·nal·ly, adverbnon·di·ag·o·nal, adjective, nounnon·di·ag·o·nal·ly, adverb

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diagonal

British Dictionary definitions for diagonal


/ (daɪˈæɡənəl) /



Derived Formsdiagonally, adverb

Word Origin for diagonal

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



1540s (implied in diagonally), from Middle French diagonal, from Latin diagonalis, from diagonus "slanting line," from Greek diagonios "from angle to angle," from dia- "across" (see dia-) + gonia "angle," related to gony "knee" (see knee (n.)). As a noun, from 1570s.

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for diagonal


[ dī-ăgə-nəl ]


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.