| HOS | health opinion survey; Holt-Oram syndrome; human osteosarcoma; hypoosmotic swelling [test] |
|---|---|
| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
| POS | periosteal osteosarcoma; physician order set; point of service; polycystic ovary syndrome; psychoorg... |