Sentence:  [T]aunt him with the licenſe of Inke: if thou <WSD>thou'ſt</WSD> him some thrice, it ſhall not be amiſſe, and as many Lyes, as will lye in thy ſheete of paper, although the ſheete were bigge enough for the w:Great Bed of Ware 
Meaning of the word marked with <WSD> tags:  To address (a person) using the pronoun "thou", especially as an expression of contempt or familiarity.