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stepsister

American  
[step-sis-ter] / ˈstɛpˌsɪs tər /

noun

  1. one's stepfather's or stepmother's daughter by a previous marriage.

stepsister British  
/ ˈstɛpˌsɪstə /

noun

  1. a daughter of one's stepmother or stepfather by a union with someone other than one's father or mother respectively

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of stepsister

late Middle English word dating back to 1400–50; step-, sister

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Related: ‘I’m part of a blended family that didn’t blend well’: My stepsister added her mailing address to our mother’s bank account.

From MarketWatch • Feb. 18, 2026

I could relate to those feelings of shame and despair she felt when she realized she was the stepsister.

From Salon • Apr. 18, 2025

And all the dreamier if they put that team in her town — and not that stepsister city across the river.

From Los Angeles Times • Apr. 8, 2025

Baena's surviving family includes his mother Barbara Stern and stepfather Roger Stern; father Scott and stepmother Michele Baena; brother Brad Baena; stepsister Bianca Gabay and stepbrother Jed Fluxman.

From BBC • Jan. 7, 2025

Ash stood up when the fire was lit and turned to face her stepsister.

From "Ash" by Malinda Lo

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.