| OT | Old Tuberculin |
|---|---|
| AT | abdominal thrusts; achievement test; Achilles tendon; Achard-Thiers [syndrome]; adaptive thermogenes... |
| HOT | health-oriented telecommunication; human old tuberculin; hyperbaric oxygen therapy; Hypertension Opt... |
| OA | obstructive apnea; occipital artery; occipito-anterior; occiput anterior; octanoic acid; ocular albi... |
| OAA | Old Age Assistance; Older Americans Act; Opticians Association of America; oxaloacetic acid |