Sentence:  Bud swelled his chest and laid his hand on Jeff′s shoulder. “Just to show you I′m not a <WSD>piker</WSD>,” he cried recklessly, “I′ll bet you twenty-five dollars I can beat your Skeeter with my Smoky horse that I rode in here. Is it a go?” 
Meaning of the word marked with <WSD> tags:  One who bets or gambles only with small amounts of money.