The word "Islam" itself means "Submission to Allah." The religion of Islam is not named after a person as in the case of "Christianity" which was named after Jesus Christ, "Buddhism" after Gutama Buddha , "Marxism" after Karl Marx, and "Confucianism" after Confucius.
Similarly, Islam is not named after a tribe like "Judaism" after the tribe of Judah and "Hinduism" after the Hindus. The Arabic word "Islam" means the submission or surrender of one's will to the will of the only true god worthy of worship, "Allah" (known as God "the Father" in Christianity).
Anyone who does indeed submit to the will of Allah as required by Islam is termed a "Muslim," which means one who has submitted to the will of Allah. Many people in the West have developed the sad misinformed trend of calling Islam "Muhammadenism" and it's followers "Muhammadins." This is a totally foreign word to Muslims and unrecognized by them. No Muslim has ever called his religion "Muhammadenism" or called himself a "Muhammadin."