sister-in-law

[sis-ter-in-law]

noun

plural

sisters-in-law 

1. the sister of one's spouse.

2. the wife of one's brother or sister.

3. the wife of one's spouse's sister or brother.

sister-in-law

noun

1. the sister of one's husband or wife

2. the wife of one's brother

Word History and Origins

Origin of sister-in-law¹

First recorded in 1400–50; late Middle English syster in lawe; sister, in, law ¹; from Middle English in-lawe “in law,” i.e., “a person within the regulation and protection of the law,” based on the prohibition by Roman civil law and, later, Christian canon law, of marriages within four degrees of consanguinity, i.e., up to and including first cousins

Example Sentences

She was driven from Venice to Riverside by her sister-in-law.

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"My brother's two children were there. Two boys. The elder one passed away, the younger one is missing. My relatives, my sister-in-law, is in the ICU. What should I do?" he said.

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Rachel was given away by her brother Simon, while her sister-in-law Emma had two important roles - as both maid of honour and best man.

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But just the way that she was — and she said that, I think it was her sister-in-law, was just going through the same thing.

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Mrs Nias said her sister-in-law could "only just" see over the dashboard and was having problems with spatial awareness.

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Related Words

• aunt 
• cousin 
• father 
• folk 
• mother 
• niece 
• sibling 
• uncle