For Scrooge (and Scrooge McDuck!) Christmas is 'humbug' - a fraudulent commercial trick aimed at 'picking a man's pocket'. And this was at a time when the Christmas shopping season began late Christmas Eve!
In general English 'humbug' describes insincere or hypocritical speech - Scrooge accuses all around him of only pretending to be interested in the plight of the poor. For British readers there is also a countable noun that makes dentists cry, 'Bah! Humbug! - all the way to the bank. This humbug is a striped candy/sweet .
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