# PSA vs pus

> English confusable word pair

## The two words

### PSA
*noun · frequency rank #15,483*
Initialism of polysialic acid.

### pus
*noun · IPA /pʌs/ · frequency rank #28,336*
A whitish-yellow or yellow substance composed primarily of dead white blood cells and dead pyogenic bacteria, normally found in regions of bacterial infection.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/vs/psa-vs-pus