# mex vs Mr

> 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.

### Mr
*noun · frequency rank #192*
Abbreviation of Mister.

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