PA

Noun
an electronic amplification system used as a communication system in public areas

Noun
a Mid-Atlantic state; one of the original 13 colonies

Noun
an informal term for a father; probably derived from baby talk

Noun
a unit of pressure equal to one newton per square meter

Noun
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead

n.
A shortened form of Papa.