| Skoliose | scoliosis |
| Skolius | amphibrach |
| Koloss | colossus |
| Ökologe | ecologist |
| Molise | Molise |
| Solist | soloist |
| solide | robust well founded respectable |
| Symbiose | symbiosis |
| Silikose | pneumonoultramicroscopicsilicovolcanoconiosis |
| Sklerose | sclerosis |
| -skopie | -scopy |
| Skoliometer | scoliometer |
| Skonto | discount cash discount early payment discount settlement discount |
| Skooter | bumper car dodgem |
| Skopje | Skopje |
| Skorpion | scorpion Scorpio |
| Kolloid | colloid |
| Kolonel | minion |
| Kolchos | kolkhoz |
| Kolibri | hummingbird |