That could imply that they are descended from a common ancestor, Proto-Italo-Celtic, which can be partly reconstructed by the comparative method. Scholars who believe that Proto-Italo-Celtic was an identifiable historical language estimate that it was spoken in the 3rd or 2nd millennium BCE somewhere in South-Central Europe.
Hellenic is the branch of the Indo-European language family whose principal member is Greek. In most classifications, Hellenic consists of Greek alone, but some linguists use the term Hellenic to refer to a group consisting of Greek proper and other varieties thought to be related but different enough to be separate languages, either among ancient neighboring languages or among modern ...