# piston vs proton

> English confusable word pair

## The two words

### piston
*noun · IPA /ˈpɪstən/ · frequency rank #15,677*
A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)

### proton
*noun · IPA /ˈpɹəʊ.tɒn/ · frequency rank #16,779*
A positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element, composed of two up quarks and a down quark.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/piston-vs-proton