Modifying definitions. A way to rationalize your position

There have been many definitions that have been abused or modified to suite a persons narrative. This is nothing more than a rationalization of their belief. This is a very common occurance yet not many people address the issue. What should we do when people redefine words to fit their view? Can we correct the redefining? Or should we work with their definition to demonstrate they're still wrong? These questions are fundamental to address the redefinition of words to suite a narrative