Public accountant.
Power amplifier.
Public Act.
Pennsylvania, a state of the United States of America
Papua, a province of Indonesia
Pará, a state of Brazil
Palestinian Authority
Proto-Algic (sometimes abbreviated PAc to distinguish it from Proto-Algonquian)
Proto-Athapaskan
Proto-Algonquian (sometimes abbreviated PAn to distinguish it from Proto-Algic, but usually just abbreviated PA with Proto-Algic being abbreviated PAc)
A health care professional trained and licensed to perform a role similar to that of a physician but with somewhat narrower limits of authority; physician assistants and nurse practitioners have enough capabilities to be physician extenders, providing primary care and allowing physicians to spread their time across more patients.