Sentence:  “As an inventor,” Bob Mason suggested, “you're a howling success at shooting <WSD>craps</WSD> ! If I were as free of spavins, ringbone, saddle-galls, and splints as you are, I'd have that nanny-goat in here, hog-tie her, flop her and let the boy help himself. ...” 
Meaning of the word marked with <WSD> tags:  a game of gambling, or chance, where the players throw dice to make scores and avoid crap