# mex vs Mx

> English confusable word pair

## The two words

### mex
*noun · frequency rank #30,134*
The mex of a subset of a well-ordered set is the smallest value from the whole set that does not belong to the subset.

### Mx
*noun · IPA /mɪks/ · frequency rank #18,635*
A gender-neutral title used instead of Mr (Mister), Mrs (Mistress), etc.

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