Initialism of absolute ceiling. • Initialism of access control. • Initialism of account current. • Initialism of anterior chamber. • Initialism of adult contemporary (a radio format). • Initialism of adenylyl cyclase. • Initialism of adjuvant chemotherapy. • Initialism of air conditioning. • Initialism of air conditioner. • Initialism of air corps. • Initialism of aircraftman. • Initialism of alternating current (often used to indicate an alternating potential rather than a current). • supply of electric energy via a public electricity grid • Initialism of area code. • Initialism of army corps. • Initialism of athletic club. • Initialism of author's correction. • Initialism of automobile club. • Initialism of Auxiliary Collier (a naval coal transport that travels with the fleet to provide coal for coal-powered warships). • Initialism of axiom of choice. • Initialism of assistant commissioner, a police rank used in London's Metropolitan Police. • Companion of the Order of Australia. • Initialism of aviation cadet. • Initialism of ammonium chloride. • Initialism of autonomous county. • Initialism of armor class. • singular of ACs (“autistics and cousins”). • Initialism of administrative custody. • Initialism of Anglo-Catholic. • Initialism of asphalt concrete. • Initialism of asphalt cement. • Initialism of asphalt content.