OA

Officers` Association
Found on http://www.encyclo.co.uk/visitor-contributions.php

OA

Osteoarthritis.
Found on http://www.astrazeneca.com/ncm.xhtml?node=glossary&letter=14

Oa

(from the article `Romania`) ...these offer some magnificent scenery. This portion of the Carpathians is bounded on the eastern side by a zone of softer flysch. For some 250 ...
Found on http://www.britannica.com/eb/a-z/o/1

OA

Oil-Air, a cooling classification for transformers now classified as ONAN. Oil type, Natural convection flow through cooling equipment and in windings, & Air external cooling medium.
Found on http://www.youngco.com/young2.asp?ID=4&Type=3

OA

Type: Abbreviation Definitions: 1. Abbreviation for occipitoanterior position.
Found on http://www.medilexicon.com/medicaldictionary.php?t=62005

Oa

Oa is a fictional planet that lies at the center of the DC Comics universe. Since its inception, Oa has been the planetary citadel of the Guardians of the Universe and the headquarters of the Green Lantern Corps. It first appeared in Green Lantern vol 2 #1, when the Guardians summoned Hal`s `energy duplicate` so they could hear of his origin. =...
Found on http://en.wikipedia.org/wiki/Oa

OA

Opportunity Attack, see Attack of Opportunity
Found on http://rpggeek.com/wiki/page/RPG_Glossary

OA

Osteoarthritis, degenerative joint disease
Found on http://www.library.illinois.edu/vex/vetabbrev.htm
No exact match found