The term 'dead set (on)' is a phrase used to describe someone who is determined and resolute in their commitment to something. The two crossword solutions for this phrase are 'BENT' and 'hellbent'. 'BENT' is a four-letter word meaning to be determined or resolute, while 'hellbent' is an eight-letter word meaning to be determined or resolute to an extreme degree. Both words can be used to describe someone who is dead set on achieving something.