English
endonym
From endo- (“inside”) + -onym (“name”).
A compound of endo- ‘inside’ + -onym ‘name’
Today it means
noun A name used by a group or category of people (an ingroup) to refer to themselves or their language, as opposed to a name given to them by other groups (outgroups).
Language periods are conventional ranges, not dates for this word.
Etymograph / endonym