The phrase "top aide" refers to the most important assistant or advisor of a person, typically someone in a position of power or authority. Full definition
During his earlier remarks, he referred to last month's conviction of the governor's former top aide on corruption charges. (recordonline.com)
His comments came during private budget talks with top aides, a source close to the governor said. (nypost.com)
And as the clock ticks down to the budget deadline, secondary matters are often decided by top aides and then approved by their bosses. (timesunion.com)