Sentence:  The Celebrity, by arts unknown, induced Mrs. Judge Short and two other ladies to call at Mohair on an afternoon when Mr. Cooke was trying a trotter on the track. The three returned wondering and charmed with Mrs. Cooke; they were <WSD>sure</WSD> she had had no hand in the furnishing of that atrocious house. 
Meaning of the word marked with <WSD> tags:  Certain in one's knowledge or belief.