How does a vicar differ from a rector? Is a marquis a lord? Where are the Home Counties? Is someone who is dead chuffed happy or angry? Americans reading British literature, come upon such unfamiliar terms and generally have to rely on contextual clues. For the legions of readers of Dickens and Trollope, of Agatha Christie, John LeCarre, and P.D. James, of Muriel Spark and Iris Murdoch, of Noel Coward and Tom Stoppard--to name a few--as well as...