half brother

noun

1. brother.

half-brother

noun

1. the son of either of one's parents by another partner

Word History and Origins

Origin of half brother¹

Middle English word dating back to 1300–50

When To Use

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.