Sentence:  The grand thing is to get rid of dogged sulks and <WSD>coltishness</WSD>—of that wayward, swerving, hesitating gait, which says, “Here's my foot, and there's my foot,” or “There is a lion in the street, I cannot go forth!” 
Meaning of the word marked with <WSD> tags:  The quality of being lively, playful and undisciplined.