Jihadism (also jihadist movement, jihadi movement and variants) is a 21st-century neologism found in the Western languages to describe Islamist militant movements perceived as a military movement "rooted in Islam" and "existentially threatening" to the West. It has been described as a "difficult term to define precisely", because it remains a recent neologism with no single, generally accepted meaning. The term "jihadism" first appeared in South Asian media and was adopted by Western journalists in the aftermath of September 11 attacks. It has since been applied to various insurgent and terrorist movements whose ideology is based on the notion of jihad.