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Number & MeasureGreekEnglish

Parallel

/ˈpærəlɛl/adjective

Running side by side at a constant distance and never meeting.

The Greek roots

παρά
pará
beside
+
ἀλλήλων
allḗlōn
of one another

Literally: beside one another

The story of the word

Παράλληλος is built on the reciprocal pronoun ἀλλήλων, so the word means beside-each-other rather than merely alongside something. Euclid's fifth postulate about parallel lines resisted proof for two thousand years, and the failed attempts to derive it produced non-Euclidean geometry. The figurative English use, drawing a parallel between two events, arrives in the sixteenth century.

How it travelled
Ancient Greek → Latin → Middle French → English
First recorded
16th century

The same roots elsewhere

Other languages reached for exactly the same Greek pieces.

Same family

parallelogramparallaxparallelepiped

In a sentence

The two roads run parallel for a mile before the river splits them.

Built on the same root

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