Sentence:  I was having lunch not long ago ( apologies to N. V. Peale ) with three distinguished historians ( one <WSD>specializing</WSD> in the European Middle Ages , one in American history , and one in the Far East ) , and I asked them if they could name instances where the general mores had been radically changed with `` deliberate speed , majestic instancy '' ( Francis Thompson 's words for the Hound of Heaven 's pursuit ) by judicial fiat . 
Meaning of the word marked with <WSD> tags:  become more focus on an area of activity or field of study