parallel (v.) Look up parallel at Dictionary.com
1590s, from parallel (n.).
parallel (adj.) Look up parallel at Dictionary.com
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- (1) "beyond"). As a noun from 1550s. Parallel bars as gymnastics apparatus are recorded from 1868.