big sister

American  

noun

1. an elder sister.

2. (sometimes initial capital letters) a woman who individually or as a member of an organized group undertakes to sponsor or assist a girl in need of help or guidance.

3. (sometimes initial capital letters) a young woman in the junior or senior class in college who advises a young woman in the freshman class on studies, social activities, etc., often as a part of a sorority program.

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Example Sentences

See Examples For:

big sister

Olivia Cusack says her big sister was the person "I looked up to my whole life", while for Emily Reilly, her cousin Maddy's the one who "used to get us in trouble with my dad".

From BBC ● Sep. 19, 2026

Taken at a gangster party in City Terrace in 1996, the author and her big sister Maria stare stone-faced, as if daring us to read.

From Los Angeles Times ● Sep. 9, 2026

And although the phrase was thrown at Ariana Grande before a screening of “Wicked,” her work as Glinda was big sister at best.

From Salon ● May 10, 2026

What she found was that the relationship went beyond business; she sees her agent as part negotiator, part therapist, part big sister.

From The Wall Street Journal ● Mar. 4, 2026

She had been like a big sister to him.

From "Messenger" by Lois Lowry

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