“Fundamentalism” is a word many around the world have grown accustomed to hearing and associating with Islam in the last few years--especially after the attacks by Al-Qaeda on the World Trade Center and the Pentagon in the United States on September 11, 2001.
Nevertheless, the term did not originate within the Muslim world, nor was the definition always connected to Islam.
Fundamentalism used to have a fairly generic meaning, especially “fundamentalism” spelled with a lower case “f”. In 2000, Grant Wacker, a professor at the Duke University Divinity School in the United States, defined “fundamentalism” as “a global religious impulse, particularly evident in the twentieth century that seeks to recover and publicly institutionalize aspects of the past that modern life has obscured.”
On the other hand, Wacker explained that “Fundamentalism” with an upper case “F” refers to “a religious movement specific to Protestant culture in the United States in the late nineteenth and early twentieth centuries.” Fundamentalism, therefore, prior to 9/11 was understood as having an association with Christianity.
But post-September 11 the common definition of the word changed. No longer is there a common distinction made in English between the lower and upper-case spelling. The Concise Oxford Dictionary of Current English now defines “fundamentalism” as the “strict maintenance of ancient or fundamental doctrines of any religion, especially Islam.”
And the connection that has been drawn between "fundamentalism" and Islam has been made outside the English language. The Real Academia Española, for example, which monitors the Spanish language throughout the Spanish speaking world, identifies “fundamentalism” specifically with Islam: “movimiento religioso y político de masas que pretende restaurar la pureza islámica mediante la aplicación estricta de la ley coránica a la vida social” (a religious and political mass movement that tries to restore Islamic purity with the strict application of the Quranic law to social life).
In common speech, "fundamentalism” is now rarely used when referring to Christianity or Judaism, although it could be a term of reference if one uses the still-existing definition provided by the Collins English Dictionary: “the belief in the original form of a religion or theory, without accepting any later ideas.