The term 'harder to outwit' can be summarized by two crossword solutions: CAGIER (6 letters) and slier (5 letters). CAGIER is an adjective that means crafty, sly, or shrewd. It is derived from the French word 'CAGE, ' which means CAGE. Slier is an adjective that means crafty, sly, or cunning. It is derived from the Old English word 'slie, ' which means sly. Both words describe someone who is difficult to outwit due to their cunning and shrewdness.