Source : Webster's Revised Unabridged Dictionary (1913)

Briticism \Brit"i*cism\, n.
   A word, phrase, or idiom peculiar to Great Britain; any
   manner of using a word or words that is peculiar to Great
   Britain.

Source : WordNet®

Briticism
     n : an expression that is limited to English as spoken by
         Englishmen (especially as contrasted with American
         English) [syn: {Anglicism}, {Britishism}]