| AO | abdominal aorta; achievement orientation; acid output; acridine orange; ankle orthosis; anodal openi... |
|---|---|
| OS | 1) Opening Snap 2) Orthopedic(Osteo)-Surgery; 정형 외과 3) Ocu... |
| A2-OS | aortic second sound, opening snap |
| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
| AVO | aortic valve opening; aortic valve orifice; atrioventricular opening |