المعنى الاصطلاحي :

Any statement, action, or belief that takes one outside the fold of Islam.

الشرح المختصر :

"Kufr Akbar" (Major disbelief) is by the heart, the tongue, and by the organs. It could be denial by the heart, or hatred against Allah the Almighty, His verses, or His Messenger, may Allah’s peace and blessings be upon him. It could be an explicit statement such as blaspheming against Allah the Exalted. It could be an explicit action such as prostrating to an idol, or slaughtering for others than Allah. "Kufr Akbar" is divided into five categories: 1. Disbelief of Rejection and Denial: This type of disbelief could be expressed by the heart, which is rare amongst the disbelievers. It could also be expressed by the tongue or the organs, by concealing the truth and refusing to submit to it outwardly despite knowing it inwardly; such as the disbelief of the Jews regarding Muhammad, may Allah’s peace and blessings be upon him. 2. Disbelief of Arrogance: It is abandoning the truth by refusing to learn it or act upon it; whether it is a statement, an action, or a belief such as the disbelief of "Iblees" (Satan). 3. Disbelief of Hypocrisy: It is denial with the heart while showing submission. 4. Disbelief of Aversion: It is complete aversion from the religion by turning one"s hearing, heart, and knowledge away from what the Prophet, may Allah"s peace and blessings be upon him, came with. The proof lies in the verse where Allah the Almighty says (what means): {But those who disbelieve turn away from what they were warned.} [Sūrat al-Ahqāf: 3] 5. Disbelief of Doubt and Uncertainty: It is hesitation in following the truth, or in acknowledging it. One is required to be certain about what the Messenger came with is the truth. Whoever questions this undeniable truth has committed the disbelief of doubt.