put up (one's) dukes
old-fashioned To raise one's fists in preparation for a fight. Often said as a command. I put up my dukes, expecting him to strike me at any moment. I ain't gonna let nobody insult my good character—come on and put up your dukes!
put up one's dukes
Fig. to be prepared to fight. He's telling you to put up your dukes. Put up your dukes and be a man!