Where does “senior” come from?

senior (Latin) comes from Latin senex, from Proto-Indo-European sénos — old.

senior (Latin): older, elder; rather old; a lord, sir; an abbot

Definitions

Step	Language	Word	Meaning
1	Latin	senex	old, aged, elderly; old person, old man, old...
2	Proto-Indo-European	sénos	old

senior — Etymology, Origin & Word History | Etymology Explorer