Sentence:  But the professor's voice had risen slightly in a question as he read "Jimmy <WSD>Willie</WSD> Hall" off the class card. The professor had intended no rudeness and he made this clear by nodding in ackowledgement to Jim's "Heah", but someone in the back of the room had sniggered and this churlishness to a stranger had embarrassed Ellen, embarrassed all the more because she, too, had smiled at the ludicrous sound. 
Meaning of the word marked with <WSD> tags:  A male given name, diminutive of William.