Pre-Greek

Short definition from Wiktionary

Proper noun

1. 1
   A hypothetical language (or languages) conjectured to have been spoken in prehistoric Greece before the arrival of Proto-Greek speakers, and used to explain the large number of non-Indo-European words found in Ancient Greek.

Adjective

1. 1
   Of or relating to such a language or its speakers.
2. 2
   Alternative form of Pre-Greek.