Islamization (also spelled Islamisation, see spelling differences; Arabic: أسلمة aslamah), Islamicization or Islamification (pejorative Muhammadization) is the process of a society's shift towards Islam, such as found in Sudan, Pakistan, Iran, Malaysia, or Algeria. In contemporary usage, it may refer to the perceived imposition of an Islamist social and political system on a society with an indigenously different social and political background.
The English synonyms, muslimization and arabization, in use since before 1940 (e.g., Waverly Illustrated Dictionary) convey a similar meaning. Muslimization has recently been used as a term coined to describe the overtly Muslim practices of new converts to the religion who wish to reinforce their newly acquired religious identity.
Arabization describes a growing cultural influence on a non-Arab area that gradually changes into one that speaks Arabic and/or incorporates Arab culture. It was most prominently achieved during the 7th-century Arabian Muslim conquests which spread the Arabic language, culture, and—having been carried out by Arabian Muslims as opposed to Arab Christians or Arabic-speaking Jews—the religion of Islam to the lands they conquered. The result: some elements of Arabian origin combined in various forms and degrees with elements taken from conquered civilizations and ultimately denominated "Arab", as opposed to "Arabian".