When you say something like "She lives outwith our catchment area," or, "This is outwith my control," you are using a Scottish word.  Perhaps it lingers from the old Edinburgh legal community, I don't know, but "outwith" is a Scottish word.  The same goes for "leet."  We talk about "the long leet," and the "short leet."  This too is a Scottish word.  Yes, news to me too.  Thanks to Graham Williamson from the University of Dundee for pointing it out.  (Interestingly, he also said that only people from Scotland say "I'm going to my bed."  South of the border there is no "my.")