| 1 | English | unofficial | Not officially established; Not acting with... |
| 2 | English | official | Of or pertaining to an office or public trust;... |
| 3 | Middle English | official | An underling of a member of the clergy, often... |
| 4 | Old French | official | court official; chamber pot; official; certified... |
| 5 | Latin | officiālis | — |
| 6 | Latin | officium | duty, service; office; obligation, an obligatory... |
| 7 | Latin | opificium | work |
| 8 | Latin | opifex | Someone who does work ; worker, maker, framer,... |
| 9 | Latin | Ops | earth goddess, fertility deity |
| 10 | Latin | oscen | any bird by whose song cries augurs divined... |
| 11 | Latin | opscen | — |
| 12 | Latin | ob- | towards; against |
| 13 | Latin | obolus | obolus |
| 14 | Ancient Greek | ὀβολός | obol, obolus, used at Athens as both a weight and... |
| 15 | Ancient Greek | ὀβελός | a spit, rod; a horizontal line |
| 16 | Ancient Greek | βέλος | missile, arrow, dart; weapon; something quickly... |