From Longman Dictionary of Contemporary Englishhave/get the measure of somebodyhave/get the measure of somebodyBritish EnglishJUDGE to know what someone’s strengths and weaknesses are, so that you are able to deal with them or defeat them She soon got the measure of her opponent. → measure
Examples from the Corpus
have/get the measure of somebody• He may have the measure of the John Gosden-trained Anshan, running from stall 15.• Booth and Rowntree were more concerned with getting the measure of poverty than with trying to devise a general theory about it. 