noun
criminal insurrection; crime of insurrection
Legal term for the crime of insurrection or rebellion against the state, as defined in criminal law.
内乱罪は刑法で定められている重罪の一つです。
The crime of insurrection is one of the serious offenses stipulated in the Penal Code.
内乱 means 'civil war' or 'internal disturbance' broadly, while 内乱罪 specifically refers to the criminal charge of insurrection.
Compound of 内乱 (internal disturbance) and 罪 (crime). The exact historical derivation is uncertain, but the term is a modern legal coinage.