# sac vs SI

> English confusable word pair

## The two words

### sac
*noun · IPA /sæk/ · frequency rank #11,789*
A bag or pouch inside a plant or animal that typically contains a fluid.

### SI
*name · frequency rank #5,453*
International System of Units

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