| Termen/ Term | Nr. apariții/ No. occurrences |
| OGLANICULUI | 4 |
| OGLANICULUI(ZONA) | 1 |
| OHIO | 2 |
| OKINAWA | 4 |
| OLANDA | 49 |
| OLANDA (?) | 5 |
| OLANDA ?L:CAMAND. ? | 1 |
| OLEANUL INDIAN | 1 |
| OLIVENCA | 1 |
| OLONEZ(?) | 2 |
| OLTET | 1 |
| OLTINA | 1 |
| OLYMPIA | 1 |
| OMAICIN | 1 |
| OMBILIN | 1 |
| OMEI-SHAN | 4 |
| OMISIEN | 2 |
| OMSK | 1 |
| ONETANGI | 1 |
| ONGUIDAI | 1 |
| ONOFRE | 3 |
| ONTARIO | 8 |
| ONTARIO (ZONA) | 1 |
| ONTARIO LENNON | 2 |
| OOSTVOORNE | 1 |
| OPROIU | 2 |
| ORAN | 1 |
| ORASUL BICAZ | 1 |
| ORATAVA | 1 |
| ORIJARVI | 3 |
| ORIJORVI | 1 |
| OROTAVA | 1 |
| OROTOVA | 1 |
| ORSK | 1 |
| ORSTOM | 2 |
| OSAKA | 10 |
| OSHIMA | 1 |
| OST-TURKESTAN | 2 |
| OSTROM | 3 |
| OSTROV | 1 |
| OSUCHOWA NOWA | 1 |
| OT | 19 |
| OTARU | 4 |
| OUA GUINEE | 1 |
| OVIFAK | 2 |
| OXOFORD | 1 |
| OZERKI-OSSA | 1 |
| OANTU | 6 |
| OBIDOS PARA | 1 |
| OBIRSIA CLOSANI | 2 |