Having a position in the lead; foremost:
Highest in quality, achievement, performance, etc.; most excellent
Outstandingly good of its kind; of exceptional merit, virtue, etc.
The definition of important is having great significance or consequence.
Find another word for top-level. In this page you can discover 29 synonyms, antonyms, idiomatic expressions, and related words for top-level, like: leading, superior, supreme, excellent, important, high-echelon, top-ranking, TopLevelShell, unmap, PopupMenu and subwindow.