half sister

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Origin of half sister

Middle English word dating back to 1150–1200
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


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.

Where does half sister come from?

The first records of the term half sister come from the 1100s. The word half refers to the fact that a half sister shares one biological parent with a sibling, not two. Still, half sister are considered blood relatives.

It’s not uncommon for people to have a half-sibling. This always involves one’s parent having a child with another partner. Circumstances vary, but such situations often involve the death of a parent, a separation, or a divorce.

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How is half sister used in real life?

People use terms like half brother and half sister to specify how siblings are related. A lot of people simply call their half sister their sister.


Try using half sister!

True or False? 

If a person’s mother and father got divorced and each had a daughter with another spouse, both of the daughters would be considered this person’s half sisters.

How to use half sister in a sentence

British Dictionary definitions for half sister


the daughter of either of one's parents by another partner
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