blood brother
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.
Origin
1350-1400;
Middle English
Related forms
blood brotherhood,
noun
British Dictionary definitions for
blood brother
blood brother
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
Slang definitions & phrases for
blood brother
blood brother
noun phrase
A fellow black;
blood
(1960+ Black)