Simple Definition of blood brother
: a man or boy who has promised to be loyal to another man or boy usually in a ceremony in which they mix their blood
Full Definition of blood brother
1 : a brother by birth
2 : one of two men pledged to mutual loyalty by a ceremonial use of each other's blood
Examples of blood brother in a sentence
He would never betray me—he's my blood brother.
First Known Use of blood brother
Seen and Heard
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