Source : Webster's Revised Unabridged Dictionary (1913)

Parallel \Par"al*lel\, n.
   1. A line which, throughout its whole extent, is equidistant
      from another line; a parallel line, a parallel plane, etc.

            Who made the spider parallels design, Sure as De
            Moivre, without rule or line ?        --Pope.

   2. Direction conformable to that of another line,

            Lines that from their parallel decline. --Garth.

   3. Conformity continued through many particulars or in all
      essential points; resemblance; similarity.

            Twixt earthly females and the moon All parallels
            exactly run.                          --Swift.

   4. A comparison made; elaborate tracing of similarity; as,
      Johnson's parallel between Dryden and Pope.

   5. Anything equal to, or resembling, another in all essential
      particulars; a counterpart.

            None but thyself can be thy parallel. --Pope.

   6. (Geog.) One of the imaginary circles on the surface of the
      earth, parallel to the equator, marking the latitude;
      also, the corresponding line on a globe or map.

   7. (Mil.) One of a series of long trenches constructed before
      a besieged fortress, by the besieging force, as a cover
      for troops supporting the attacking batteries. They are
      roughly parallel to the line of outer defenses of the
      fortress.

   8. (Print.) A character consisting of two parallel vertical
      lines (thus, ||) used in the text to direct attention to a
      similarly marked note in the margin or at the foot of a
      page.

   {Limiting parallels}. See under {Limit}, v. t.

   {Parallel of altitude} (Astron.), one of the small circles of
      the sphere, parallel to the horizon; an almucantar.

   {Parallel of declination} (Astron.), one of the small circles
      of the sphere, parallel to the equator.

   {Parallel of latitude}.
      (a) (Geog.) See def. 6. above.
      (b) (Astron.) One of the small circles of the sphere,
          parallel to the ecliptic.