parallel (adj.)

1540s, from Middle French parallèle (16c.) and directly from Latin parallelus, from Greek parallelos "parallel," from para allelois "beside one another," from para- "beside" (see para- (1)) + allelois "each other," from allos "other" (from PIE root *al- "beyond"). As a noun from 1550s. Parallel bars as gymnastics apparatus are recorded from 1868.

parallel (v.)

1590s, from parallel (n.).