See also: sister in law



From Middle English suster-in-lawe; equivalent to sister +‎ -in-law.



sister-in-law (plural sisters-in-law or (colloquial, nonstandard) sister-in-laws)

  1. A female relative of one's generation, separated by one degree of marriage:
    1. The sister of one's spouse.
      Though they are not twins, my sister-in-law resembles my wife in almost every way.
    2. The wife of one's sibling.
      My sister-in-law and my brother both met while they were on vacation in Jamaica.
  2. (less common) Co-sister-in-law: The wife of one's sibling-in-law.
    1. The wife of the sibling of one's spouse.
    2. The sister of the spouse of one's sibling.

Usage notesEdit

The plural sister-in-laws is occasionally seen, especially in American English, but this is considered incorrect by most sources; see, for example, [1].



  • Ah Soh (elder brother’s wife) (Singapore, slang)

Derived termsEdit

Related termsEdit


The translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Wiktionary:Entry layout § Translations.