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half sister
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half-sister
half-sisternounthe daughter of either of one's parents by another partner
half sister
Americannoun
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half sisters
plural
noun
Usage
What does half sister mean? A half sister is a sister who is related to her sibling(s) through only one parent. This typically means that they share only one biological parent (not both). For example, when a person’s parent has a daughter with another partner (who is not the person’s parent), the daughter is considered the person’s half sister. The term half brother is used in the same way. Half-sibling is a gender-neutral way of saying the same thing. In contrast, the words stepsister, stepbrother, and stepsibling refer to those who have a sibling relationship (often based on the remarriage of their parents to other partners) but who do not share a biological parent. The word half in half sister and its related terms only refers to the biological relationship. Half sisters may have close relationships with their siblings, and many people simply call their half sister their sister. Modifiers such as maternal and paternal are sometimes used to specify which biological parent the siblings have in common. Example: Over the holidays, I got together with my maternal half sister and my paternal half brother and we had a great time.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of half sister
Middle English word dating back to 1150–1200
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.
See Examples For:
The girl, the half sister of Sarah's son, was born on Christmas Day 2022, and the family became a trio the following December.
From BBC ● Dec. 19, 2025
Ms. Kuehn met her father’s half sister, Ruth, only once, in 1987.
From The Wall Street Journal ● Dec. 4, 2025
Breasia was the half sister of Dinkins’ son, and investigators have said both children were staying the night with him at the apartment where he was living with a girlfriend.
From Seattle Times ● Aug. 10, 2023
Paparazzi spotted Corinne, her half sister Anelise and Anelise’s mom, Kristin Grannis, at the facility in May.
From Los Angeles Times ● Jul. 10, 2023
Back when they had met, neither of them had known about his half sister, Hazel.
From "The Mark of Athena" by Rick Riordan
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He will not be part of Belgium's royal line of succession, unlike his half-sister Princess Louise and half-brothers Prince Aymeric and Prince Nicolas.
From BBC ● Aug. 20, 2026
If Truelove ends up in prison for a long stint, his half-sister figures, he will at least get a bed and three meals.
From Los Angeles Times ● Jul. 24, 2026
Although he kept contact with his father while in care, his coordinator helped him establish relationships with his wider family, including aunts, uncles, cousins and a half-sister.
From BBC ● Jun. 4, 2026
The baby’s half-sister would be easier for the older couple to take care of.
From Salon ● Mar. 24, 2026
“My half-sister lost her kid, my nephew, end of last year. It’s rough.”
From "American Gods" by Neil Gaiman
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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.