from The American Heritage® Dictionary of the English Language, 4th Edition
- abbr. alternating current
- abbr. area code
from Wiktionary, Creative Commons Attribution/Share-Alike License
- absolute ceiling
- account current
- adult contemporary, a radio format
- air conditioning; air conditioned, usually: A/C
- air corps
- all clear, as in button on electronic calculator
- alternating current; often used to indicate an alternating potential rather than a current, as in 110V AC.
- anno Christi, in the year of Christ.
- ante Christum before Christ.
- ante cibum before meals.
- appellation contrôlée
- area code
- army corps
- as charged, as in: guilty as charged, usually: a/c
- athletic club
- audible chuckle
- author's correction
- automobile club
- Auxiliary Collier - a naval coal transport that travels with the fleet to provide coal for coal powered warships
- axiom of choice
- Companion of the Order of Australia.
- aviation cadet
- abbr. Aceh, an autonomous province of Indonesia.
- abbr. Acre, a state of Brazil.
Sorry, no etymologies found.