| Abbreviation | Definition |
|---|---|
| SLW | Spectral- Line Weighted |
| Sm | Samarium |
| SMA | Styrene Malic Anhydride |
| SMAC | SupraMolecular Activation Cluster |
| SMART | Synergistically Molecular Attractor-Repulsor Theory |
| SMDC | Small Molecule Drug Conjugate |
| SMILES | Simplified Molecular Input Line Entry System |
| SMOC | Standard Mean Ocean Chloride |
| SMR | Small Modular Reactor |
| SMT | Smooth Matrix Top |
| Sn | Stannum (Tin) |
| SN | Steric Number |
| Sn | tin |
| SNALP | Stable nucleic acid lipid particle |
| SNALP | Stable nucleic acid lipid particles |
| SNAP | Strontium Nitrate Acetone Peroxide |
| SND | Sulfur Chemiluminescence Detectors |
| SNF | SuperNatant Fluid |
| SNIC | Singapore National Institute of Chemistry |
| SO | sulfur monoxide |