Where does “geronto-” come from?

geronto- (English) comes from Ancient Greek γέρων, from Proto-Hellenic *géronts.

geronto- (English): Pertaining to old age or elderly people

Definitions

Step	Language	Word	Meaning
1	Ancient Greek	γέρων	an old man; elders, i.e. a ruling or advisory...
2	Proto-Hellenic	*géronts	—

geronto- — Etymology, Origin & Word History | Etymology Explorer