|The Simple English Wiktionary has a definition for: jihad.|
Jihad is an Arabic word meaning "to struggle". Muslims (believers in Islam) use this word to talk about defending the faith and protecting their family and nation, as well as defending innocent people. It can also mean fighting with yourself to become a better person. It is an official part of Shi'a Islam, but it is not an official part of Sunni Islam, though some call it the sixth pillar of Islam.