Sentence:  Selkirk persuaded eighty men and four officers to go to Red River where they were to serve as a military force to protect his settlers from the hostile Northwest Company which resented the intrusion of farmers into the <WSD>fur</WSD> traders ' empire . 
Meaning of the word marked with <WSD> tags:  dense coat of fine silky hairs on mammals (e.g., cat or seal or weasel)