Formal term for an act that breaks a rule, law, or regulation. Often used in legal or official contexts.
This violation will be severely punished.
Reports of offenses are increasing.
違反 is a more common and general word for 'violation', while 違犯行為 is a formal compound explicitly meaning 'act of violation'.
Compound of 違犯 (violation) and 行為 (act). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning.