par·al·lel (păr'ə-lĕl')
adj.

1. Being an equal distance apart everywhere: dancers in two parallel rows. See Usage Note at absolute.
2. Mathematics.
   1. Of, relating to, or designating two or more straight coplanar lines that do not intersect.
   2. Of, relating to, or designating two or more planes that do not intersect.
   3. Of, relating to, or designating a line and a plane that do not intersect.
   4. Of, relating to, or designating curves or surfaces everywhere equidistant.
3. 1. Having comparable parts, analogous aspects, or readily recognized similarities: the parallel lives of two contemporaries.
   2. Having the same tendency or direction: parallel motives and aims.
4. Grammar. Having identical or equivalent syntactic constructions in corresponding clauses or phrases.
5. Music.
   1. Moving in the same direction at a fixed interval: parallel motion; parallel fifths.
   2. Having the same tonic. Used of scales and keys: C minor is the parallel minor scale of C major.
6. Electronics. Denoting a circuit or part of a circuit connected in parallel.
7. Computer Science.
   1. Of or relating to the simultaneous transmission of all the bits of a byte over separate wires: a parallel port; a parallel interface.
   2. Of or relating to the simultaneous performance of multiple operations: parallel processing.

adv.
In a parallel relationship or manner: a road and a railway that run parallel.

n.

1. Mathematics. One of a set of parallel geometric figures, such as lines or planes.
2. 1. One that closely resembles or is analogous to another: a unique event, without parallel in history.
   2. A comparison indicating likeness; an analogy.
3. The condition of being parallel; near similarity or exact agreement in particulars; parallelism.
4. Any of the imaginary lines representing degrees of latitude that encircle the earth parallel to the plane of the equator.
5. Printing. A sign indicating material referred to in a note or reference.
6. Electronics. An arrangement of components in a circuit that splits the current into two or more paths. Used chiefly in the phrase in parallel.

tr.v., -leled, also -lelled, -lel·ing, -lel·ling, -lels, -lels.

1. To make or place parallel to something else: paralleled the ditch to the highway.
2. To be or extend parallel to: a trail that parallels the crater rim.
3. To be similar or analogous to: claimed that fetal development parallels the evolution of the species.
4. To be or provide an equal for; match.
5. To show to be analogous; compare or liken: critics who have paralleled the novel's plot to an ancient myth.

[Latin parallēlus, from Greek parallēlos : para-, beside; see para-¹ + allēlōn, of one another (from allos, other).]

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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