Sentence:  They burned the old gun that used to stand in the dark corner up in the garret, close to the stuffed fox that always <WSD>grinned</WSD> so fiercely. Perhaps the reason why he seemed in such a ghastly rage was that he did not come by his death fairly. And why else was he put away up there out of sight?—and so magnificent a brush as he had too. 
Meaning of the word marked with <WSD> tags:  To show the teeth, like a snarling dog.