parallel

American  

[par-uh-lel, -luhl] / ˈpær əˌlɛl, -ləl /

adjective

1. extending in the same direction, equidistant at all points, and never converging or diverging.

   Parallel rows of trees lined two ends of the parking lot.

2. having the same direction, course, nature, or tendency; corresponding; similar; analogous.

   Canada and the United States have many parallel economic interests.

   Synonyms:

   alike, like

   Antonyms:

   unique, unlike, divergent

3. Geometry.

   1. (of straight lines) lying in the same plane but never meeting no matter how far extended.

   2. (of planes) having common perpendiculars.

   3. (of a single line, plane, etc.) equidistant from another or others (usually followed by to orwith ).

4. Electricity. consisting of or having component parts connected in such a way that all positive terminals are connected to one point and all negative terminals are connected to a second point, the same voltage being applied to each component.

   a parallel circuit.

5. Music.

   1. (of two voice parts) progressing so that the interval between them remains the same.

   2. (of a tonality or key) having the same tonic but differing in mode.

      A major and A minor are parallel keys.

6. Computers.

   1. of or relating to the apparent or actual performance of more than one operation at a time by the same or different devices (distinguished from serial).

      Some computer systems join more than one CPU for parallel processing.

   2. of or relating to the simultaneous transmission or processing of all the parts of a whole, as all the bits of a byte or all the bytes of a computer word (distinguished from serial).

7. Grammar. consisting of matched syntactic elements in corresponding positions.

   In the sentence “I have three cats and two dogs,” “three cats” and “two dogs” are in parallel structure.

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noun

1. a parallel line or plane.

2. anything parallel or comparable to something else in direction, course, nature, or tendency.

3. Also called parallel of latitude.  Geography.

   1. an imaginary circle on the earth's surface formed by the intersection of a plane parallel to the plane of the equator, bearing east and west and designated in degrees of latitude north or south of the equator along the arc of any meridian.

   2. the line representing this circle on a chart or map.

4. something identical or similar in essential respects; match; counterpart.

   It's a struggle to diagnose a case history without a known parallel.

   Synonyms:

   equivalent, body double, twin, duplicate, mate, equal

   Antonyms:

   opposite

5. correspondence or analogy.

   These two cases have some parallel with each other.

6. a comparison of things as if regarded side by side.

7. Electricity. an arrangement of the components, such as resistors, of a circuit in such a way that all positive terminals are connected to one point and all negative terminals are connected to a second point, the same voltage being applied to each component.

8. Fortification. a trench cut in the ground before a fortress, parallel to its defenses, for the purpose of covering a besieging force.

9. Printing. a pair of vertical parallel lines (‖) used as a mark for reference.

10. Theater. a trestle for supporting a platform parallel top.

verb (used with object)

parallels, present (3rd person singular) paralleled, past participle, past parallelled, past participle, past paralleling, present participle parallelling present participle

1. to provide or show a parallel for; match.

2. to go or be in a parallel course, direction, etc., to.

   The road parallels the river.

3. to form a parallel to; be equivalent to; equal.

4. to show the identity or similarity of; compare.

5. to make parallel.

idioms

1. in parallel,

   1. at the same time or in conjunction.

      When you are at school, your growth and change is taking place in parallel with fellow students who are also growing and changing.

   2. Electricity. (of the components of a circuit) arranged in such a way that all positive terminals are connected to one point and all negative terminals are connected to a second point, the same voltage being applied to each component.

parallel British  

/ ˈpærəˌlɛl /

adjective

1. separated by an equal distance at every point; never touching or intersecting

   parallel walls

2. corresponding; similar

   parallel situations

3. music

   1. Also: consecutive.  (of two or more parts or melodies) moving in similar motion but keeping the same interval apart throughout

      parallel fifths

   2. denoting successive chords in which the individual notes move in parallel motion

4. grammar denoting syntactic constructions in which the constituents of one construction correspond to those of the other

5. computing operating on several items of information, instructions, etc, simultaneously Compare serial

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noun

1. maths one of a set of parallel lines, planes, etc

2. an exact likeness

3. a comparison

4. Also called: parallel of latitude.  any of the imaginary lines around the earth parallel to the equator, designated by degrees of latitude ranging from 0° at the equator to 90° at the poles

5. 1. a configuration of two or more electrical components connected between two points in a circuit so that the same voltage is applied to each (esp in the phrase in parallel )

   2. ( as modifier ) See series

      a parallel circuit

6. printing the character (∥) used as a reference mark

7. a trench or line lying in advance of and parallel to other defensive positions

verb

1. to make parallel

2. to supply a parallel to

3. to be a parallel to or correspond with

   your experience parallels mine

parallel Scientific  

/ păr′ə-lĕl′ /

1. Of or relating to lines or surfaces that are separated everywhere from each other by the same distance.

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1. Any of the imaginary lines encircling the Earth's surface parallel to the plane of the equator, used to represent degrees of latitude.

2. See illustration at longitude

Other Word Forms

Derived Forms

• parallelless
  adjective
• subparallel
  adjective
• nonparallel
  adjective
• parallelable
  adjective
• unparallel
  adjective
• parallelly
  adverb

Conjugated Forms

Present

• have paralleled
  perfect
• have parallelled
  perfect
• has parallelled
  perfect 3rd person singular
• has paralleled
  perfect 3rd person singular
• have been paralleling
  perfect progressive
• am parallelling
  progressive 1st person singular
• are paralleling
  progressive
• has been paralleling
  perfect progressive 3rd person singular
• has been parallelling
  perfect progressive 3rd person singular
• are parallelling
  progressive
• am paralleling
  progressive 1st person singular
• parallels
  singular 3rd person
• is paralleling
  progressive 3rd person singular
• parallelling
  participle
• paralleling
  participle
• is parallelling
  progressive 3rd person singular
• have been parallelling
  perfect progressive

Past

• had paralleled
  perfect
• had parallelled
  perfect
• were parallelling
  progressive plural
• was paralleling
  progressive singular
• was parallelling
  progressive singular
• had been paralleling
  perfect progressive
• paralleled
  participle
• parallelled
  simple
• paralleled
  simple
• had been parallelling
  perfect progressive
• were paralleling
  progressive plural
• parallelled
  participle

Future

• will parallel
  simple
• will have parallelled
  perfect
• will have paralleled
  perfect
• will be paralleling
  progressive
• will have been paralleling
  perfect progressive
• will be parallelling
  progressive
• will have been parallelling
  perfect progressive

Etymology

Origin of parallel

First recorded in 1540–50; from Latin parallēlus, from Greek parállēlos “side by side,” from par- par- + állēlos “one another” ( see allo-)

Explanation

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.

Example Sentences

The Iran war could be a good parallel to that.

From Slate • Jun. 4, 2026

"Compared to the conventional approach of connecting multiple devices in parallel, this approach allowed us to significantly boost the detection sensitivity," adds Michailow.

From Science Daily • May 31, 2026

The original image was accompanied by a short piece of anonymous text, warning readers against stumbling into its disturbing parallel world.

From Barron's • May 28, 2026

The race to adapt on the battlefield has been sharpened by a parallel public relations war.

From BBC • May 28, 2026

After the service, as the remaining worshippers gathered outside the church, news whipsawed through the crowd that North Korean troops had crossed the 38th parallel.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau

Related Words

• analogy
• comparison
• corollary
• resemblance
• similarity