Sentence:  Seemingly here was an intruder who was violating custom. Moreover, the partners had come to look upon this exceedingly rich district as their exclusive property. And so their indignation was extreme./ "The low-down, ornery <WSD>cuss</WSD>!" said Dobbs. "The nerve of him, crowdin' in on us, just as if there wasn't lots of other places for him to go!" 
Meaning of the word marked with <WSD> tags:  A fellow, person.