diagonal
noun · adjective
Simple meaning
Joining two nonadjacent vertices.
Pronunciation
Say it like this:
dyaguhnuhlSay the bold part a little louder.
IPA pronunciation (US)
daɪˈæɡənəl
This word is pronounced essentially the same in American and British English, so one transcription covers both.
IPA (International Phonetic Alphabet) is a standard way of writing speech sounds.
Definition
Everyday modern meanings first, grouped by part of speech.
noun
geometry
A straight line connecting any two vertices of a polygon that are not adjacent
“Draw a diagonal connecting opposite corners of the square.”
geometry
A line joining non-adjacent vertices of a polygon.
Anything forming or resembling such a line, particularly
adjective
geometry
Joining two nonadjacent vertices (of a polygon or polyhedron).
Having a slanted or oblique direction.
Of or related to the cater-corner (diagonally opposite) legs of a quadruped, whether the front left and back right or front right and back left.
Having slanted or oblique lines or markings.
Word at a Glance
- Difficulty
- C1 · Advanced (estimated)
- Frequency
- Moderately Common
- Typical Use
- Neutral / general English
Word Aura™
How this word commonly comes across.
Aura for this meaning
This meaning: A straight line connecting any two vertices of a polygon that are not adjacent
Used this way, diagonal is a specialist word that usually carries little praise or criticism of its own. This is a mathematical use: it is defined precisely and belongs to working with figures and calculations rather than to ordinary conversation.
“Draw a diagonal connecting opposite corners of the square.”
- Emotional tone
- Neutral
- Formality
- Specialist/technical
- Intensity
- Not strongly marked
- How common
- Specialized
- Connotation
- Clinical and technical
- Usage feel
- Technical and specialized
Where it naturally appears
- Mathematics
- Geometry
- Academic writing
- Education/classroom
Usage note
In general conversation this sense usually needs explaining — outside its field, people reach for a plainer word.
Word Aura describes common impressions, not a measurement. Tone changes with sentence, speaker, relationship and situation.
More ways to use diagonal
- “The bishop moves on the diagonals.”noun
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Common Patterns and Combinations
How this word naturally appears with others.
Word Family
Related forms, grouped by how they connect.
Compound terms
Established multiword terms.
A square matrix with all elements not on the main diagonal equal to zero.
The diagonal of a square matrix running from the upper left entry to the lower right entry.
The diagonal of a square matrix running from the upper left entry to the lower right entry.
The diagonal of a square matrix running from the lower left entry to the upper right entry.
More about this wordSynonyms, forms, origin
Synonyms
Sense: straight line connecting any two vertices of a polygon that are not adjacent
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Dictionary data from Wiktionary via the Free Dictionary API. Simple meanings, combinations and word intelligence are built from verified reference data, no AI is used to load this page.