Sentence:  From the shrill triumph with which his name was dragged in, his crime must have been pilfering from a cathedral at least, but as both remembrancers were speaking at once it was difficult to distinguish his infamy from the scandal which <WSD>beclouded</WSD> the memory of Mrs. Saunders' brother's wife's mother—who may have been a regicide, and was certainly not a nice person as Mrs. Crick painted her. 
Meaning of the word marked with <WSD> tags:  To cast in a negative light, cast a pall over, darken.