Sentence:  For this is the <WSD>Yuletide</WSD>, and the heathen people of the forest are gathered at the thunder-oak of Geismar to worship their god, Thor. 
Meaning of the word marked with <WSD> tags:  The period of celebration of a pre-Christian festival associated with the (northern) winter solstice, later absorbed into the festival of Christmas (but sometimes recreated by modern neo-pagans).