P.A.

Noun	1.	P.A. - an electronic amplification system used as a communication system in public areas Synonyms: P.A. system, PA system, public address system, PA
Adv.	1.	p.a. - 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" Synonyms: per annum, per year, annually, each year

annually, each year, per annum, per year