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definitions

principal diagonal

noun

Mathematics. See under diagonal(def 9).

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Nearby words

  1. principal argument,
  2. principal artery of thumb,
  3. principal axis,
  4. principal boy,
  5. principal clause,
  6. principal focus,
  7. principal ideal,
  8. principal ideal domain,
  9. principal nursing officer,
  10. principal optic axis

Origin of principal diagonal

First recorded in 1960–65

Definition for principal diagonal (2 of 2)

diagonal

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

adjective

noun

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

British Dictionary definitions for principal diagonal

diagonal

/ (daɪˈæɡənəl) /

adjective

noun

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 principal diagonal

diagonal

adj.

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 principal diagonal

diagonal

[ dī-ăg′ə-nəl ]

Adjective

Connecting two nonadjacent corners in a polygon or two nonadjacent corners in a polyhedron that do not lie in the same face.

Noun

A diagonal line segment.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.