In math, parallel means two lines that never intersect — think of an equal sign. Figuratively, parallel means similar, or happening at the same time. A story might describe the parallel lives of three close friends.

Parallel is from Greek parallēlos, from the prefix para-, "beside," plus allēlōn, "of one another," from allos, "other." As a noun, a parallel is a way in which things resemble each other — you might draw parallels between the Vietnam War and the U.S. invasion of Iraq. In specialized use, a parallel can mean one of the imaginary circles on the surface of the Earth that are parallel to the equator — the 49th parallel divides the U.S. and Canada.

Definitions of parallel
  1. adjective
    being everywhere equidistant and not intersecting
    parallel lines never converge”
    “concentric circles are parallel
    “dancers in two parallel rows”
    able to be compared or worthy of comparison
    (especially of vectors) parallel but oppositely directed
    situated or running side by side
    nonconvergent, nonintersecting
    (of lines, planes, or surfaces) never meeting or crossing
    symmetric, symmetrical
    having similarity in size, shape, and relative position of corresponding parts
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    slanting or inclined in direction or course or position--neither parallel nor perpendicular nor right-angled
    intersecting at or forming right angles
    tending to come together from different directions
    divergent, diverging
    tending to move apart in different directions
    at an angle to the horizontal or vertical position
    slanting diagonally across the grain of a fabric
    cata-cornered, catacorner, cater-cornered, catercorner, catty-corner, catty-cornered, kitty-corner, kitty-cornered
    slanted across a polygon on a diagonal line
    crabwise, sideways
    (of movement) at an angle
    connecting two nonadjacent corners of a plane figure or any two corners of a solid that are not in the same face
    (of e.g. lines or paths) not parallel; converging
    having oblique angles
    forming a right angle
    orthogonal, rectangular
    having a set of mutually perpendicular axes; meeting at right angles
    having the axis perpendicular to the base
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  2. noun
    (mathematics) one of a set of parallel geometric figures (parallel lines or planes)
    parallels never meet”
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    type of:
    a combination of points and lines and planes that form a visible palpable shape
  3. noun
    an imaginary line around the Earth parallel to the equator
    synonyms: latitude, line of latitude, parallel of latitude
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    polar circle
    a line of latitude at the north or south poles
    horse latitude
    either of two belts or regions near 30 degrees north or 30 degrees south; characterized by calms and light-baffling winds
    either of two parallels of latitude about 23.5 degrees to the north and south of the equator representing the points farthest north and south at which the sun can shine directly overhead and constituting the boundaries of the Torrid Zone or tropics
    type of:
    a spatial location defined by a real or imaginary unidimensional extent
  4. verb
    be parallel to
    “Their roles are paralleled by ours”
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    type of:
    agree, check, correspond, fit, gibe, jibe, match, tally
    be compatible, similar, or consistent; coincide in their characteristics
  5. verb
    make or place parallel to something
    “They paralleled the ditch to the highway”
    synonyms: collimate
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    type of:
    alter, change, modify
    cause to change; make different; cause a transformation
  6. noun
    something having the property of being analogous to something else
    synonyms: analog, analogue
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    a close parallel of a feeling, idea, style, etc.
    type of:
    the quality of being similar
  7. adjective
    of or relating to the simultaneous performance of multiple operations
    parallel processing”
    synchronal, synchronic, synchronous
    occurring or existing at the same time or having the same period or phase
  8. verb
    duplicate or match
    synonyms: duplicate, twin
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    type of:
    agree, check, correspond, fit, gibe, jibe, match, tally
    be compatible, similar, or consistent; coincide in their characteristics
Word Family

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