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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:
My dad is in Northern California with his family, including my half brother.
From The Wall Street Journal ● Jan. 6, 2026
When Murray heard the news, he spoke with James Lafferty, who played his on-screen half brother, Nathan Scott, on the show.
From Los Angeles Times ● Nov. 20, 2024
Aramco said it had received instructions to dial back expansion from the ministry of energy, which is run by Prince Abdulaziz bin Salman, the older half brother of the crown prince.
From New York Times ● Jan. 30, 2024
She was saved by her half brother Billy after he smelled smoke.
From Salon ● Dec. 27, 2023
Maria—relieved to be away from the conventions of society and to reunite with her half brother Caspar—tried to embrace this structured, spiritual way of life.
From "The Girl Who Drew Butterflies: How Maria Merian's Art Changed Science" by Joyce Sidman
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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
The remaining members of EW&F, including original members Philip Bailey, White’s half-brother Verdine, and Ralph Johnson, form one of the few nostalgia acts that can still draw people to arenas.
From Salon ● Jun. 7, 2026
Ferrer later learns of another half-brother, her father’s son; these fraught relationships are the pillars of a gorgeous meditation on belonging.
From Los Angeles Times ● May 1, 2026
My mother took one pair of oars and my fairly ancient half-brother took the other, and off we would go.
From "Boy: Tales of a Childhood" by Roald Dahl
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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.