Kafir ( ; plural , or ; feminine ; feminine plural or ) is an Arabic and Islamic term which, in the Islamic culture, refers to a person who disbelieves in God as per Islam, denies his authority, or rejects the tenets of Islam; or simply all those who are not Muslims—those who do not believe in the guidance of Islamic prophet Muhammad. Thus the term is the opposite of the term Muslim. The term is often translated as 'infidel,' 'pagan,' 'rejector,' 'denier,' 'disbeliever,' 'unbeliever,' 'nonbeliever,' and 'non-Muslim.' The term is used in different ways in the Quran, with the most fundamental sense being 'ungrateful' (toward God). means 'unbelief' or 'non-belief,' 'to be thankless,' 'to be faithless,' or 'ingratitude.' The opposite term of is ('faith'), and the opposite of is ('believer'). A person who denies the existence of a creator might be called a .
is sometimes used interchangeably with (, those who practice polytheism), another type of religious wrongdoer mentioned frequently in the Quran and other Islamic works. (Other, sometimes overlapping Quranic terms for wrong-doers are ('villain', 'oppressor') and ('sinner', 'fornicator').) Historically, while Islamic scholars agreed that a polytheist/ was a , they sometimes disagreed on the propriety of applying the term to Muslims who committed a grave sin or to the People of the Book. The Quran distinguishes between and People of the Book, reserving the former term for idol-worshippers, although some classical commentators considered the Christian doctrine to be a form of .
In modern times, is sometimes applied towards self-professed Muslims, particularly by members of Islamist movements. The act of declaring another self-professed Muslim a is known as , a practice that has been condemned but also employed in theological and political polemics over the centuries. A or is a historical term for non-Muslims living in an Islamic state with legal protection. were exempt from certain duties assigned specifically to Muslims if they paid the poll tax () but were otherwise equal under the laws of property, contract, and obligation according to some scholars, whereas others state that religious minorities subjected to the status of (such as Hindus, Christians, Jews, Samaritans, Gnostics, Mandeans, and Zoroastrians) were inferior to the status of Muslims in Islamic states. Jews and Christians were required to pay the and taxes, while others, depending on the different rulings of the four , might be required to convert to Islam, pay the , be exiled, or killed under the Islamic death penalty.
In 2019, Nahdlatul Ulama, the world's largest independent Islamic organization, issued a proclamation urging Muslims to refrain from using the word to refer to non-Muslims, because the term is both offensive and perceived as "theologically violent".
Etymology
The word is the active participle of the verb , from root K-F-R. As a pre-Islamic term it described farmers burying seeds in the ground. One of its applications in the Quran has also the same meaning as farmer. Since farmers cover the seeds with soil while planting, the word implies a person who hides or covers. Ideologically, it implies a person who hides or covers the truth. Arabic poets personify the darkness of night as , perhaps as a survival of pre-Islamic Arabian religious or mythological usage.
The noun for 'disbelief', 'blasphemy', 'impiety' rather than the person who disbelieves, is .
In the Quran
The distinction between those who believe in Islam and those who do not is an essential one in the Quran. , and its plural , is used directly 134 times in Quran, its verbal noun is used 37 times, and the verbal cognates of are used about 250 times.
By extension of the basic meaning of the root, 'to cover', the term is used in the Quran in the senses of ignore/fail to acknowledge and to spurn/be ungrateful. The meaning of 'disbelief', which has come to be regarded as primary, retains all of these connotations in the Quranic usage. In the Quranic discourse, the term typifies all things that are unacceptable and offensive to God. Whereby it is not necessary to deny the existence of God, but it suffices to deviate from his will as seen in a dialogue between God and Iblis, the latter called a . According to Al-Damiri (1341–1405) it is neither denying God, nor the act of disobedience alone, but Iblis' attitude (claiming that God's command is unjust), which makes him a . The most fundamental sense of in the Quran is 'ingratitude', the willful refusal to acknowledge or appreciate the benefits that God bestows on humankind, including clear signs and revealed scriptures.