Susan Ferrari has a good post on the definition of "fundamentalism" and its application to Islam. As she points out, the term was originally coined to describe Christians who took the Bible literally. Hence, calling someone a "Muslim fundamentalist" is almost redundant, because the Qur'an is met to be taken literally - this point is as fundamental to Islam as the God-Christ relationship is to Christianity.

She also mentions another definition from the OED, that of "strict adherence to ancient or fundamental doctrines, with no concessions to modern developments in thought or customs." This is what most people think of when they say "Islamic fundamentalism." However, when you scratch the surface, you find problems here, too, because most of the supposedly ancient doctrines of Muslim fundamentalists are fairly modern. As Dr. Morgan often says, "Calling the Taliban 'medieval' is an insult to the Middle Ages." This was, after all, the age in which the Muslim world was the center of science and technology, a confident civilization unafraid to borrow the best of other cultures in creating its own synthesis.

What Islamic fundamentalist groups are basically doing is arguing that society should be built around conservative Islamic norms from which they see it as straying. They believe these norms were practiced in the earliest days of Islam; however, they're really just modern interpretations of older customs frequently lacking the spirit of the original of which they are shadows. For example, one thing some groups have done is take the four categories of human action in Islamic law - forbidden, reprehensible, laudible, and mandatory - and eliminated the middle two, which goes against 1400 years of Muslim thought. Unfortunately I know little of Islamic law, so I can't cite specifics beyond that, but you get the idea.

Modern scholars usually prefer the term "Islamist" because of these problems with the word "fundamentalist." However, I still prefer fundamentalist. Why? I think that beyond the scholarly debate, the word "fundamentalist" has simply come to stand for strongly held conservative beliefs and practices. More importantly, the idea most people would get if I used "Islamist" is probably that these groups were trying to "Islamize" everything (well, I guess they are), which would leave their beliefs with the title of "Islam." Certainly Islamic fundamentalism is as legitimate a form of Islam and Christian fundamentalism is to Christianity, but I'd rather we didn't paint all Islam with that brush - I feel annoyed enough when the religious right is simple referred to in the media as "Christian groups" or something - speaking as someone who's strongly Christian and who has a lot of rather liberal Christian friends, I sort of feel that coming out against "Islamism" is only a notch better than the "Islamic groups" some reporters fall into.

At root, this is really a problem of cross-cultural terminology - trying to describe Islamic civilization using language developed with specific definitions for Western civilization. This is always a very chancy proposition that usually leads to some level of misunderstanding. The only way to really understand Islamist movements is to go back and see how they fit into the broad sweep of Islamic history and culture - then you will understand the nuances necessary with any term you choose in discussing them. Unfortunately, this project takes more time than most people have, leaving us as the mercy of our own "general knowledge" and media reports.