| Abbreviation | Definition |
|---|---|
| SIE | Superficial Inferior Epigastric |
| SIES | Self Inflicted Exhaustion Syndrome |
| sig | signal |
| SIG | Surface ImmunoGlobulin |
| SIJ | Sacroiliac joint |
| SIK | Skeletal Inverse Kinematics |
| SIMETH | Simethicone |
| SIMV | Synchronized Intermitted Modulation Ventilation |
| SIN | self-inactivating |
| SINE | System For Integrated Noise Exposures |
| SING | Solar plexus, Instep, Nose, Groin |
| SIPP | Staten Island Physician Practice |
| SIPPA | Saskatchewan International Physician Practice Assessment |
| SIPT | Sensory Integration and Praxis Test |
| SIPW | Southern Indiana Physicians For Women |
| SIR | Small Instance Relaxation |
| SIR | Susceptible, Infected, and Recovered |
| siRNA | small interfering ribonucleic acid |
| SIRS | Systemic Inflammatory Response Syndrome |
| SIS | Self Injury Support |