Sentence:  Be not too rigidly cenſorious, / A ſtring may <WSD>jar</WSD> in the beſt maſter's hand, / And the moſt ſkilful archer miſs his aim; / But in a poem elegantly writ, / I would not quarrel with a ſlight miſtake, / Such as our nature's frailty may excuſe; ... 
Meaning of the word marked with <WSD> tags:  To (cause something to) give forth a rudely tremulous or quivering sound; to (cause something to) sound discordantly or harshly.