Things that have depth and can be rotated in space are three-dimensional. Everything around you that you can touch or move around—your sneaker, your dog, the rug on the floor—is three-dimensional.

Dimensionality can be a tricky quality to understand, but it helps to think of a line connecting two points as one-dimensional and a flat plane or shape, like a triangle drawn on paper, as two-dimensional. When you add depth to a shape, you get a three-dimensional object: a triangle becomes a pyramid, for example. When a story or other work of art is so well-made and detailed that it's believable, you can also describe it as three-dimensional.

Definitions of three-dimensional
  1. adjective
    involving or relating to three dimensions or aspects; giving the illusion of depth
    “lifelike three-dimensional characters”
    “a three-dimensional account of conditions under the new government”
    synonyms: 3-dimensional, third-dimensional, three-d
    having or involving or marked by several dimensions or aspects
  2. adjective
    having three dimensions
    synonyms: cubic
    blockish, blocky
    resembling a block in shape
    box-shaped, boxlike, boxy
    resembling a box in rectangularity
    shaped like a brick
    cube-shaped, cubelike, cubical, cubiform, cuboid, cuboidal
    shaped like a cube
    of a crystal system characterized by three equal axes at right angles
    having three dimensions
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    linear, one-dimensional
    of or in or along or relating to a line; involving a single dimension
    planar, two-dimensional
    involving two dimensions
    lying on the same line
    arranged in a line
    resembling a line
    rectilineal, rectilinear
    characterized by a straight line or lines
    lying in the same plane
    having a relatively broad surface in relation to depth or thickness
    placoid, platelike
    as the hard flattened scales of e.g. sharks
    flattened, planate
    having been flattened
    flat; like a table in form
    show more antonyms...
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