The term 'crowning achievement' is used to describe a great accomplishment or success. The crossword solutions for this term include CAPSTONE, BULLSEYE, PINNACLE, SMASHHIT, GRANDSLAM, SHOWPIECE, MAGNUMOPUS, and MASTERWORK. Each of these words can be used to describe a great success or accomplishment, with CAPSTONE referring to the final piece of a project, BULLSEYE referring to hitting the target, PINNACLE referring to the highest point, SMASHHIT referring to something that is very successful, GRANDSLAM referring to a home run, SHOWPIECE referring to something that is impressive, MAGNUMOPUS referring to something that is very large and powerful, and MASTERWORK referring to something that is a masterpiece.