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 <WSD>mottoes</WSD> like/ <small>  Here's rattling good luck and roaring good cheer, / With lashings of food and great hogsheads of beer.</small> ...” 
Meaning of the word marked with <WSD> tags:  A sentence, phrase, or word, prefixed to an essay, discourse, chapter, canto, or the like, suggestive of its subject matter; a short, suggestive expression of a guiding principle; a maxim.