As a Noun: 1. A person who believes in Islam and lives according to its rules. English = Muslim, Moslem. 2. The religion of the Muslims, which teaches that there is only one God and that Mohammed is His prophet. English = Islam. As a Verb or Adjective: 1. To relate to Islam. English = (be) Muslim, (be) Moslem, (be) Islamic. 2. To worship and pray after the custom of Muslims.