We all like conciseness. The ideal is a short name such as "Higgs boson" that specifies exactly what you mean, and which conveys that precise meaning to everyone who hears the name. However in politics names are rarely as precise and the same words can mean very different things to different listeners. Accordingly some words can be very damaging to use.
I want to explain why we should never call people such as the Woolwich killers or the insurgents in Mali "jihadis" or "jihadists".