Proportional

How to spell proportional

12 letters · 4 syllables

How to pronounce proportional

Say the part in capitals loudest.

What does proportional mean?

1. adjectiveCorresponding in size, amount, or degree to something else, so that the two change in step.

Proportional in a sentence

• The fine is proportional to the amount of unpaid tax.

• Each partner receives a share proportional to the capital they invested.

Where does proportional come from?

Language of origin: Latin

This word descends from the Latin proportio, which meant a comparative relation or due share between things, formed from the phrase pro portione, literally 'according to each part'. The portio element meant a portion or share, and is the same root that gives English the everyday word 'portion'. The medieval Latin proportionalis added the adjective ending to describe something kept in fixed ratio, and English took it in through Old French during the late 1300s, often in the context of mathematics and music where exact ratios mattered. Over time the meaning broadened from strict numerical ratio to any relationship in which one quantity grows or shrinks in step with another. The spelling trap lives in the middle: the unstressed 'por' followed by 'tion' encourages writers to drop or swap letters, even though the steady 'portion' inside the word is a reliable anchor.

How the word is built

• pro- (forth, in front)
• portion (a share, from Latin portio)
• -al (adjective suffix)