the civilization of Muslims collectively which is governed by the Muslim religion
Islam is predominant in northern Africa, the Middle East, Pakistan, and Indonesia.
source: WordNet 3.0
the monotheistic religious system of Muslims founded in Arabia in the 7th century and based on the teachings of Muhammad as laid down in the Koran
Islam is a complete way of life, not a Sunday religion. The term Muhammadanism is offensive to Muslims who believe that Allah, not Muhammad, founded their religion.