1
general::
Phrase(s): Blood will have blood.
Prov. People will use violence to get revenge for violent acts; murderers will themselves be murdered. • Although no one suspected him of the murder he had committed, Parker lived in fear. He had heard that blood will have blood. • I am afraid that the two gangs will never stop killing each other. Blood will have blood.
McGrawhill's American Idioms And Phrasal Verbs