Is·lam (?s-läm?, -l?m?, ?z-, ?s?läm?, ?z?-)n.1. A monotheistic religion characterized by the doctrine of absolute submission to God and by reverence for Muhammad as the chief and last prophet of God.2. a. The people or nations that practice Islam; the Muslim world.b. The civilization developed by the Muslim world.[Arabic ‘isl?m, submission, from ‘aslama, to surrender, resign oneself, from Syriac ‘a?lem, to make peace, surrender, derived stem of ?lem, to be complete; see ?lm in Semitic roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.Islam (??zl??m) n1. (Islam) the religion of Muslims, having the Koran as its sacred scripture and teaching that there is only one God and that Mohammed is his prophet; Mohammedanism2. (Islam) a. Muslims collectively and their civilizationb. the countries where the Muslim religion is predominant[C19: from Arabic: surrender (to God), from aslama to surrender] Is?lamic adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Is?lam (?s?l?m, -?læm, ?z-, ??s l?m, ??z-) n. 1. the religion of the Muslims, as set forth in the Koran, that teaches that there is only one God, Allah, and that Muhammad is His prophet. 2. the whole body of Muslim believers, their civilization, and the countries in which theirs is the dominant religion. [1605?15;