Semantics

DON'T
"Use the terms 'jihadist' or 'mujahedeen' in conversation to describe the terrorists. ... calling our enemies 'jihadis' and their movement a global 'jihad' unintentionally legitimizes their actions."

DO
"Use the terms 'violent extremist' or 'terrorist.' Both are widely understood terms that define our enemies appropriately and simultaneously deny them any level of legitimacy."

source

The Bush administration has launched a new front in the war on terrorism, this time targeting language.
Federal agencies, including the State Department, the Department of Homeland Security and the National Counter Terrorism Center, are telling their people not to describe Islamic extremists as "jihadists" or "mujahedeen," according to documents obtained by The Associated Press. Lingo like "Islamo-fascism" is out, too.
The reason: Such words may actually boost support for radicals among Arab and Muslim audiences by giving them a veneer of religious credibility or by causing offense to moderates.