Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun blood_brother

2 senses of blood brother

Sense 1
brother, blood brother -- (a male with the same parents as someone else; "my brother still lives with our parents")
       => male sibling -- (a sibling who is male)

Sense 2
blood brother -- (a male sworn (usually by a ceremony involving the mingling of blood) to treat another as his brother)
       => ally, friend -- (an associate who provides cooperation or assistance; "he's a good ally in fight")