# sister-out-law

> English word · Noun

## Definitions
1. The sister of one's boyfriend or girlfriend.
2. Girlfriend of one's brother or sister.
3. The sister of one's ex-spouse.

## Etymology
From sister + -out-law, by analogy to sister-in-law.

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