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half brother
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half-brother
half-brothernounthe son of either of one's parents by another partner
half brother
Americannoun
noun
Usage
What does half brother mean? A half brother is a brother who is related to his 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 son with another partner (who is not the person’s parent), the son is considered the person’s half brother. The term half sister is used in the same way. Half-sibling is a gender-neutral way of saying the same thing. In contrast, the words stepbrother, stepsister, 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 brother and its related terms only refers to the biological relationship. Half brothers may have close relationships with their siblings, and many people simply call their half brother their brother. 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 brother and my paternal half sister and we had a great time.
Etymology
Origin of half brother
Middle English word dating back to 1300–50
Compare meaning
How does half-brother compare to similar and commonly confused words? Explore the most common comparisons:
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:
Walters’ younger half brother, Noah Collins, was in second grade at the time and lived around the block from Walters and their grandparents.
From Slate ● Sep. 17, 2026
But upon her father’s death, her younger half brother Aegon — who was born after Rhaenyra was named heir — was crowned king of the Seven Kingdoms instead.
From Los Angeles Times ● Jun. 17, 2026
My dad is in Northern California with his family, including my half brother.
From The Wall Street Journal ● Jan. 6, 2026
His only loss came last year to Tommy Fury, half brother of WBC heavyweight champ Tyson Fury.
From Seattle Times ● Mar. 7, 2024
Obviously Gebu had a great deal on his mind or he would never have forgotten the coppers or those other loaves or permitted his gutter-waif half brother to keep a whole fish for himself.
From "The Golden Goblet" by Eloise Jarvis McGraw
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Their half-brother, Nick Marden, 65, says he isn’t involved.
From The Wall Street Journal ● Sep. 15, 2026
It was probably commissioned by Bishop Odo of Bayeux -- William's half-brother -- in 1077 to decorate the new cathedral in his hometown, Bayeux, according to the tapestry's home museum.
From Barron's ● Jul. 9, 2026
While he also briefly studied overseas in Switzerland, he was said to be a lot more insulated than his half-brother Kim Jong Nam.
From BBC ● Jun. 27, 2026
King Aegon II is Rhaenyra’s younger half-brother who was born after she had already been announced as Viserys’ heir.
From Los Angeles Times ● Jun. 19, 2026
My Fourth Aunt, who had been married to Dad’s half-brother, lived downstairs with her daughter, my cousin You-mei, and You-mei’s daughter, a lovely baby called Hua-hua.
From "Red Scarf Girl: A Memoir of the Cultural Revolution" by Ji-li Jiang
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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.