From Longman Dictionary of Contemporary EnglishChristmas stockingˌChristmas ˈstocking noun [countable] 
DHa long sock which children leave in their house on Christmas Eve to be filled with presents
DHa long sock which children leave in their house on Christmas Eve to be filled with presentsExamples from the Corpus
Christmas stocking• Romanov placed his hands into the box like an expectant child does with a Christmas stocking, and drew out the icon.• Gone are the days when the average man would be happy with soap on a rope in his Christmas stocking.• Some admit to paying more than £200 on toys to fill their youngster's Christmas stocking.• This book should be in the Christmas stocking of any serious aircraft enthusiast, although it would make walking difficult! 