In my search for the best synonym for the word "shrewdly," I came across several options that convey a similar meaning. After careful consideration, I believe that "astutely" is the most suitable synonym. Both words imply a sense of keen perception and cleverness when making decisions or solving problems. Other options, such as "sharply" or "wisely," come close but don't quite capture the full essence of shrewdness. In the end, "astutely" truly encapsulates the cunning and insightful nature of the word "shrewdly."