'parallel' originates from Greek, specifically the word 'parallēlos,' where 'para-' meant 'beside' and 'allēlōn' meant 'each other.'

'parallēlos' transformed into the Latin word 'parallelus,' and eventually became the modern English word 'parallel' through Old French.

Initially, it meant 'beside each other,' but over time it evolved into its current meaning of 'equidistant lines or surfaces.'