a command that is the primary provider of air combat weapon systems to the United States Air Force; operates fighter, bomber, reconnaissance, battle-management, and rescue aircraft
"The ACC serves as the central hub managing all fighter, bomber, and reconnaissance aircraft for the United States Air Force."
Initialism of author-created character, a new character who is added into a fanfic's cast of 'official' characters.
"The fanfiction editor decided to introduce an acc to give the original protagonist a rival in the second chapter."
In plain English: Acc is short for access, which means having permission to get into or use something.
"The coach sent an acc to his agent asking for advice on how to handle the contract offer."
Initialism of Association of Corporate Counsel.
"The acc at our firm specializes in corporate governance and regulatory compliance."