| OR | a logical binary relation that is true if any argument is true, and false otherwise; [o]estrogen rec... |
|---|---|
| PRBS | pseudorandom binary sequence |
| AA | abdominal aorta; acetic acid; achievement age; active alcoholic; active assistive [range of motion];... |
| OA | obstructive apnea; occipital artery; occipito-anterior; occiput anterior; octanoic acid; ocular albi... |
| PAA | partial agonist activity; phenylacetic acid; phosphonoacetic acid; physical abilities analysis; plas... |