- soot blowing on the heating surface of boiler
- sooty
- SOP
- SOPC
- S-operator
- Sophia Loren
- Sophie Marceau
- sophism
- Sophist
- Sophistes
- sophistical
- sophistication
- sophistry
- sophocarpine
- Sophocles
- sophomore’s dream
- Sophonisba
- sophora triproces treehopper
- sophorose
- Sophus Claussen
- soprano
- SOR
- SORAG
- sorbate
- sorbent