How to Spell proportion

Middle English proporcioun, proporcion "comparative relation in magnitude, ratio," borrowed from Anglo-French & Latin; Anglo-French proporcion, proporciun, borrowed from Latin prōportiōn-, prōportiō "analogy, proper spatial relation between parts" (Medieval Latin also "comparative relation in magnitude"), univerbation of prō portiōne "in the degree proper to each, proportionately" {mat|portion:1|}