The Merriam-Webster definition of jihad is: a war fought by Muslims to defend or spread their beliefs. According to the Islamic Supreme Council of America, the linguistic definition of jihad is “struggling”.
Jihad can mean many things. It can mean being a good, virtuous Muslim, as well as protecting Islam. This aspect of jihad is often exploited by extremists and the media, as extremists often wage war under the name jihad, when the war is not truly a war to protect Islam. It should be noted that protecting Islam is not a violent act; protecting Islam should be done diplomatically and peacefully.
To claim jihad militarily, Muslim religious leaders must be consulted to confirm that Islam is truly under threat before a war can be waged under the name of jihad. For example, the war between Muslims and Christian Crusaders in Medieval Ages can be labeled jihad because the religion of Islam was threatened and Muslims had to resort to violence to protect Islam.