Sentence:  Prayter said with a smile to the faces looking down, "Rilly—this train's a joke, isn't it!" / A wag yelled, "Yes—a <WSD>smutty</WSD> one!" / With raucous laughter in his ears, the parson turned and looked for Lace, feeling rather lonely. 
Meaning of the word marked with <WSD> tags:  Obscene, indecent.