Briticism
Briticism, the name for an idiom used in Great Britain and not in America, is a BARBARISM*; and should either be Britannicism or Britishism, just as Hibernicism or Irishism will do, but not Iricism. Gallicism and Scot(t)icism and Scotch are in Latin Gallicus and Scot(t)icus, but British is Britannicus. The verbal critic, who alone uses such words, should at least see to it that they are above criticism.
(*Barbarism: a word or expression that is badly formed according to traditional philiological rules)