noun (n)

• an informal term for a father; probably derived from baby talk(noun.person)

  Synonym:
  dad, dada, daddy, papa, pappa, pop
  

  source: wordnet30
• a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead(noun.substance)

  Synonym:
  atomic number 91, protactinium, protoactinium
  

  source: wordnet30
• a unit of pressure equal to one newton per square meter(noun.quantity)

  Synonym:
  pascal
  

  source: wordnet30
• a Mid-Atlantic state; one of the original 13 colonies(noun.location)

  Synonym:
  de, delaware, diamond state, empire state, first state, free state, keystone state, maryland, md, new york, new york state, ny, old line state, pennsylvania
  

  source: wordnet30
• an electronic amplification system used as a communication system in public areas(noun.artifact)

  Synonym:
  p.a., p.a. system, pa system, public address system
  

  source: wordnet30
• A shortened form of Papa.(noun)

  source: webster1913