C-Suite

What Does C-Suite Mean?
A widely-used slang term used to collectively refer to a corporation's most important senior executives. C-Suite gets its name because top senior executives' titles tend to start with the letter C, for chief, as in chief executive officer, chief operating officer and chief information officer.

Also called "C-level executives".

Investopedia explains C-Suite
The C-suite is considered the most important and influential group of individuals at a company. Being a member of this group comes with high-stakes decision making, a more demanding workload and high compensation. As "chief" titles proliferate, however, job-title inflation may decrease the prestige associated with being a member of the C-suite.