Power amplifier.
Public accountant.
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 jack of all trades.
An individual employed to do all sorts of duties.
A large decorative printing block with a central space into which any letter can be inserted, used to mark the beginning of a chapter of a book in early printing.