Parallel a. : Extended in the same direction, and in all parts equally distant; as, parallel lines; parallel planes.

Parallel a. : Having the same direction or tendency; running side by side; being in accordance (with); tending to the same result; -- used with to and with.

Parallel a. : Continuing a resemblance through many particulars; applicable in all essential parts; like; similar; as, a parallel case; a parallel passage.

Parallel n. : A line which, throughout its whole extent, is equidistant from another line; a parallel line, a parallel plane, etc.

Parallel n. : Direction conformable to that of another line,

Parallel n. : Conformity continued through many particulars or in all essential points; resemblance; similarity.

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

Parallel n. : Anything equal to, or resembling, another in all essential particulars; a counterpart.

Parallel n. : 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.

Parallel n. : 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.

Parallel n. : 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.

Parallel v. t. : To place or set so as to be parallel; to place so as to be parallel to, or to conform in direction with, something else.

Parallel v. t. : Fig.: To make to conform to something else in character, motive, aim, or the like.

Parallel v. t. : To equal; to match; to correspond to.

Parallel v. t. : To produce or adduce as a parallel.

Parallel v. i. : To be parallel; to correspond; to be like.

Example:
What's the difference between series and Parallel circuits?

Taxonomy
geodesics, plane, parallel lines, infinity, geometry, hyperbolic plane, straight lines, perpendicular, parallel line, definitions, Euclidean, great circles, parallels of latitude, angle of parallelism, free encyclopedia, hyperbolic space, Symbol, non-Euclidean geometry.

Defination from the web:
... lines a and b are parallel. We can prove this because the transversal t produces congruent angles. Given straight lines l and m, the following descriptions of line m equivalently define it as parallel to line l in Euclidean ... ( This is equivalent to Euclid's parallel postulate. ...