| suboptimal | suboptimal |
| suborbital | suborbital |
| optimal | optimal optimum |
| subatomar | subatomic |
| subliminal | subliminal |
| subtil | subtle |
| Optimat | optimate |
| Submitrale | zucchetto |
| Subroutine | subroutine |
| Substitut | surrogate |
| Suboxid | suboxide |
| Substrat | substrate |
| Subtilität | subtleness |
| subdural | subdural |
| subgingival | subgingival |
| subkrustal | subcrustal |
| subkutan | subcutaneous |
| sublim | sublime |
| sublingual | sublingual |
| subpolar | subpolar |