Sentence:  But if I'm duly sensible of this, / And if I really fear to do amiss, / How, George, how (in the name of wonder!) then, / Dares my poor, puny, scurvy, <WSD>scrattling</WSD> pen / Presume thy neat performances to trace, / And, with mean words, thy beauteous works debase 
Meaning of the word marked with <WSD> tags:  To scratch.