| Pas | pascal-second |
|---|---|
| R' | in electrocardiography, the second positive deflection during the QRS complex |
| sec | second; secondary; section |
| SMN | second malignant neoplasm; stathmin |
| SO | salpingo-oophorectomy; Schlatter-Osgood [test]; second opinion; sex offender; spheno-occipital [sync... |