Sentence:  Tom was so stunned that he had not even presence of mind enough to say "Who cares, Miss Smarty?" until the right time to say it had gone by. So he said nothing. But he was in a fine rage, nevertheless. He moped into the schoolyard wishing she were a boy, and imagining how he would <WSD>trounce</WSD> her if she were. 
Meaning of the word marked with <WSD> tags:  To beat severely; to thrash.