Where does “seigneur” come from?

seigneur (Middle French) comes from Old French seignor, from Latin senior, from Latin senex, from Proto-Indo-European sénos — old.

seigneur (Middle French): lord; sire

Definitions

Step	Language	Word	Meaning
1	Old French	seignor	lord; sire; master
2	Latin	senior	older, elder; rather old; a lord, sir; an abbot
3	Latin	senex	old, aged, elderly; old person, old man, old...
4	Proto-Indo-European	sénos	old

seigneur — Etymology, Origin & Word History | Etymology Explorer