p.a.
    adv 1: by the year; every year (usually with reference to a sum
           of money paid or received); "he earned $100,000 per
           annum"; "we issue six volumes per annum" [syn: per
           annum, p.a., per year, each year, annually]
    n 1: an electronic amplification system used as a communication
         system in public areas [syn: public address system, P.A.
         system, PA system, P.A., PA]

Pa \Pa\ (p[aum]), n.
   A shortened form of Papa.
   [1913 Webster]

PA
       Precision Architecture (HP)