AC may refer to any of the following, broken down by subject area. Science. Actinium (Ac), a chemical element; Acetaldehyde (also Ac), an organic ion; Acetate (also Ac), an organic ...
http://en.wikipedia.org/wiki/AC

AC Cars Group Ltd. formerly known as Auto Carriers Ltd. is a British specialist automobile manufacturer and one of the oldest independent car marques founded in Britain.
http://en.wikipedia.org/wiki/AC_Cars

Public Transportation Authority for western Alameda and Contra Costa Counties.
http://www.actransit.org/

Manufacturer of battery and propulsion systems for electric vehicles.
http://www.acpropulsion.com/

A four year liberal arts university affiliated with the Baptist Church. Online application, information about academics and athletics, and alumni directory.
http://www.ac.edu/