sister-in-law – Wiktionary

Angelena Iglesia

English[edit] Etymology[edit] From Middle English suster-in-lawe; equivalent to sister +‎ in +‎ law. Noun[edit] sister-in-law (plural sisters-in-law) A female relative of one’s generation, separated by one degree of marriage: The sister of one’s spouse. The wife of one’s sibling. (less common) Co-sister-in-law: The wife of one’s sibling-in-law. The wife of […]