Takfir or takfeer (Arabic: تكفير‎ takfīr) is a controversial concept in Islamist discourse, denoting excommunication, as one Muslim declaring another Muslim, or any individual, as a non-believer (kafir). The act which precipitates takfir is termed mukaffir. Contemporary formulation and usage of the term have their roots in the 20th-century Islamist theorist Sayyid Qutb's advocacy of takfirism (doctrine of excommunication) against the state or society deemed jahiliyah (state of ignorance and disbelief).