Language of special groups

Someone at the University of Melbourne kindly emailed me about the recent seizure by ordinary language of a number of specialist expressions. In particular, he drew my attention to the terms epicentre and ballistic. What disturbed this person was not so much the fact that the wider community was taking up these terms, but the misuse of them. Epicentre, as he pointed out, is a term from geology. In its technical meaning it refers to the true centre of a disturbance – the point from which earthquake waves go out. These days in ordinary language it seems to be acquiring a more general sense of simply ‘middle’. The ABC news, for example, reported the arrest of someone described as being at ‘the epicentre of a drug ring’.