| 1 | Middle English | sir | Alternative form of sire |
| 2 | Middle English | sire | Used preceding the name or title of a knight,... |
| 3 | Old French | sire | nominative singular of sieur; master, sir, lord;... |
| 4 | Vulgar Latin | seior | — |
| 5 | Latin | senior | older, elder; rather old; a lord, sir; an abbot |
| 6 | Latin | senex | old, aged, elderly; old person, old man, old... |
| 7 | Proto-Indo-European | sénos | old |