Apo. Apogee.
Apoc. Apocalypse; Apocrypha, Apocryphal.
app. Appendix; Apprentice.
A.P.R.C., Anno post Romam conditam=In the year after the building of Rome (753 B.C.).
aq., aqua=Water.
A.R., anno regni=In the year of the reign.
Ar., Arab. Arabic.
ar., arr. Arrive or Arrives, Arrival.
A.R.A. Associate of the Royal Academy.
arbor. Arboriculture.