Etymology: Latin parallelus, from Greek parallēlos, from para beside + allēlōn of one another, from allos…allos one…another, from allos other — more at else
Date: 1549
1 a: extending in the same direction, everywhere equidistant, and not meeting <parallel rows of trees>b: everywhere equally distant <concentric spheres are parallel> 2 a: having parallel sides <a parallel reamer>b: being or relating to an electrical circuit having a number of conductors in parallel c: arranged in parallel <a parallel processor>d: relating to or being a connection in a computer system in which the bits of a byte are transmitted over separate channels at the same time <a parallel port> — compare serial 3 a (1): similar, analogous, or interdependent in tendency or development (2): exhibiting parallelism in form, function, or development <parallel evolution>b: readily compared :companionc: having identical syntactical elements in corresponding positions; also: being such an element d (1): having the same tonic —used of major and minor keys and scales (2): keeping the same distance apart in musical pitch 4: performed while keeping one's skis parallel <parallel turns>