| Operationssaal | operating room theatre operating theater operating theatre surgery theater |
| Operation | surgery operation |
| Oxidationszahl | oxidation number |
| arational | arational |
| irrational | irrational |
| rational | rational |
| übernational | supranational |
| Ionisationsstab | ionization bar ionizing bar |
| relational | relational |
| optional | optional |
| Kooperation | cooperation co-operation |
| Operationszeichen | operator |
| Operator | operator administrator |
| operativ | surgical operative operational strategic |
| Personal | personnel staff human resources |
| perinatal | perinatal |
| Generations- | generational |
| generationell | generational |
| Föderation | federation |
| Föderationskreis | federal district |