p.a.

1. participial adjective.
2. per annum.
3. press agent.

1. Parents’ Association.
2. Insurance. particular average.
3. passenger agent.
4. post adjutant.
5. power of attorney.
6. press agent.
7. public-address system.
8. publicity agent.
9. purchasing agent.

abbreviation for

1. per annum

n.abbreviation of “public address” (system), attested from 1936.