pa Meaning, Definition & Usage

1. noun an informal term for a father; probably derived from baby talk
   dad; dada; papa; pop; pappa; daddy.
   
2. noun a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
   protoactinium; atomic number 91; protactinium.
   
3. noun a unit of pressure equal to one newton per square meter
   pascal.
   
4. noun a Mid-Atlantic state; one of the original 13 colonies
   Pennsylvania; Keystone State.
   
5. noun an electronic amplification system used as a communication system in public areas
   P.A.; PA system; P.A. system; public address system.
   

WordNet