OA

Officers` Association

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

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

OA

Open Agility
Found on http://www.showdogsupersite.com/actualshow/dogsho3.html
No exact match found