Takfir is a word of Arabic origin and derives from the verb "kefere" which means to cover, to hide and to be ungrateful. Takfir is used to indicate that a person has fallen into disbelief. Takfir, understood as giving the judgment of an unbeliever for a person, although he is known to be a believer and he says that he is a believer, is a term mostly used by non-Ahl al-Sunnah religious entities and especially those who have Salaf / Wahhabi perceptions about others other than themselves. It is a religious and political movement with a multifaceted and wide influence in the world Named after Mohammed b. This nomenclature found a wide area of use in religious circles outside the current, scientific and political fields
Sources: Security Terms Glossary (T.C. İçişleri Bakanlığı Kamu Düzeni ve Güvenliği Müsteşarlığı, Ankara),Türk Dil Kurumu Sözlüğü , Türkiye Diyanet Vakfı İslam Ansiklopedisi Bernard LEWİS, İnanç ve İktidar (Ortadoğu’da Din ve Siyaset)