Sentence:  “[…] the awfully hearty sort of Christmas cards that people do send to other people that they don't know at all well. You know. The kind that have mottoes like // Here's rattling good luck and roaring good cheer, / With lashings of food and <WSD>great</WSD> hogsheads of beer.nb...” 
Meaning of the word marked with <WSD> tags:  Relatively large in scale, size, extent, number (i.e. having many parts or members) or duration (i.e. relatively long); very big.