Apostasy in Islam
Apostasy in Islam (Arabic: ردة, romanized: ridda or ارتداد, irtidād) is commonly defined as the abandonment of all or part of Islam by a current or former Muslim, in thought, word, or through deed. It includes not only explicit apostasy, renunciations of the Islamic faith by converting to another religion or abandoning religion altogether, but also blasphemy or heresy by those who consider themselves Muslims, through any action or utterance which implies unbelief, including those who deny a "fundamental tenet or creed" of Islam.