# SDP vs SI

> English confusable word pair

## The two words

### SDP
*name · frequency rank #49,622*
Initialism of Social Democratic Party, a centre-left political party in the United Kingdom.

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

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