Parallel  —adj. 1 a (of lines or planes) continuously side by side and equidistant. B (foll. By to, with) (of a line or plane) having this relation (to or with another). 2 (of circumstances etc.) Precisely similar, analogous, or corresponding. 3 a (of processes etc.) Occurring or performed simultaneously. B computing involving the simultaneous performance of operations. —n. 1 person or thing precisely analogous to another. 2 comparison (drew a parallel between them). 3 (in full parallel of latitude) a each of the imaginary parallel circles of constant latitude on the earth's surface. B corresponding line on a map (49th parallel). 4 printing two parallel lines (||) as a reference mark. —v. (-l-) 1 be parallel, or correspond, to. 2 represent as similar; compare. 3 cite as a parallel instance.  in parallel (of electric circuits) arranged so as to join at common points at each end.  parallelism n. [greek, = alongside one another]