When it comes to describing a success, the phrase "big hit" is often used. However, there are many other synonyms worth exploring to add variety to your writing and speech. A "smash hit" conveys the idea of a highly popular and well-received achievement. "Grand slam" is a term commonly used in sports, referring to a home run hit with all bases occupied, but it can also mean a major victory. Another option is "blockbuster," which is typically used to describe a successful movie or book. "Knockout" conveys a powerful punch that leaves a lasting impression, while "megahit" suggests a tremendous level of impact and success.