# SIDS vs sis

> English confusable word pair

## The two words

### SIDS
*noun · frequency rank #49,048*
Acronym of sudden infant death syndrome.

### sis
*noun · IPA /sɪs/ · frequency rank #12,501*
Clipping of sister.

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