blood brother

American  

noun

1. a person's brother by birth.

2. a male person bound to another by ties of great friendship.

3. something usually associated with or thought to exist inseparably from another thing, quality, circumstance, etc..

   Humility is often the blood brother of patience.

4. a male established in a close relationship with another male through the performance of a specific ritual, as the commingling of blood.

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blood brother British  

noun

1. a brother by birth

2. a man or boy who has sworn to treat another as his brother, often in a ceremony in which their blood is mingled

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Other Word Forms

• blood brotherhood
  noun

Etymology

Origin of blood brother

Middle English word dating back to 1350–1400

Example Sentences

Blood brother to the two kittens on the floor, Frosty was a third bigger than they.

From Swamp Cat by Kjelgaard, James Arthur