# USD vs USO

> English confusable word pair

## The two words

### USD
*noun · frequency rank #7,515*
Initialism of unified school district.

### USO
*noun · frequency rank #35,573*
Unidentified submerged object or unidentified submarine object.

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