You may not have noticed it, but a senior White House counterterrorism official recently ended our war on terror, replacing it with a war against Al Qaeda, and explaining that the U.S. government shouldn't use such words as jihad because to do so would confer legitimacy on the terrorists. (Thanks to Jihad Watch.)
Zuhdi Jasser comments here on the fallacy of such an approach; the U.S. government has put itself in the position of determining who is or isn't a good Muslim, and many Islamist terrorists seeking to attack the United States are not linked to Al Qaeda.
As to what jihad means, here's an interpretation offered by Lebanese members of the Islamist Hizb al Tahrir organization. As one of them puts it: "Jihad in Islam is twofold. The first type is the offensive Jihad, in which the Muslims engage the infidels in fighting in order to bring the message of Islam to them, and to pull them from darkness and into the light."
Another clarified: "Some people tried to interpret Jihad to mean nothing more than self-defense ... In principle, Jihad is an offensive Jihad, which was instated in order to spread Islam throughout the world." (Thanks to MEMRI.)