Sentence:  When they had gone, Ma Potter opened her eyes. She said, "Pay no attention, child. Don't upset yourself. Just <WSD>humbug</WSD>, that's all." / "What do you mean?" Cora whispered. ... "You mean, telling lies?" / "Not altogether. Humbuggery is what people talk without thinking. Lies are deliberate. Are you a clever child?" 
Meaning of the word marked with <WSD> tags:  Nonsense.