diagonal

A diagonal is made out of a straight line that's set at an angle instead of straight up or across. If you picture a square and draw a line connecting the opposite corners, that’s a diagonal line.

You’ll find diagonal lines in geometry, and also in the world around you. A quarterback might throw a diagonal pass that angles across the field, or you might buy a snazzy new leotard with diagonal stripes. Diagonal can be either a noun or an adjective. You could call the steep slope of a hill a diagonal across the sky, or you could talk about the diagonal hillside reaching up toward the clouds.

Definitions of diagonal
  1. adjective
    having an oblique or slanted direction
    synonyms: aslant, aslope, slanted, slanting, sloped, sloping
    inclined
    at an angle to the horizontal or vertical position
  2. adjective
    connecting two nonadjacent corners of a plane figure or any two corners of a solid that are not in the same face
    “a diagonal line across the page”
    Synonyms:
    oblique
    slanting or inclined in direction or course or position--neither parallel nor perpendicular nor right-angled
  3. noun
    (geometry) a straight line connecting any two vertices of a polygon that are not adjacent
    see moresee less
    type of:
    straight line
    a line traced by a point traveling in a constant direction; a line of zero curvature
  4. noun
    a line or cut across a fabric that is not at right angles to a side of the fabric
    synonyms: bias
    see moresee less
    type of:
    straight line
    a line traced by a point traveling in a constant direction; a line of zero curvature
  5. noun
    (mathematics) a set of entries in a square matrix running diagonally either from the upper left to lower right entry or running from the upper right to lower left entry
    see moresee less
    type of:
    set
    (mathematics) an abstract collection of numbers or symbols
  6. noun
    an oblique line of squares of the same color on a checkerboard
    “the bishop moves on the diagonals
    see moresee less
    types:
    main diagonal, principal diagonal
    the diagonal of a square matrix running from the upper left entry to the lower right entry
    secondary diagonal
    the diagonal of a square matrix running from the lower left entry to the upper right entry
    type of:
    line
    a formation of people or things one behind another
    line
    a formation of people or things one beside another
  7. noun
    a punctuation mark (/) used to separate related items of information
    synonyms: separatrix, slash, solidus, stroke, virgule
    see moresee less
    type of:
    punctuation, punctuation mark
    the marks used to clarify meaning by indicating separation of words into sentences and clauses and phrases
Word Family
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