Sentence:  The Man who laugh'd but once, to see an Ass / Mumbling to make the cross-grained Thistles pass, / Might laugh again, to see a Jury <WSD>chaw</WSD> / The prickles of unpalatable Law. 
Meaning of the word marked with <WSD> tags:  To chew; to grind with one's teeth; to masticate (food, or the cud)