Ancient Greek contains approximately 1,000 words of unknown origin that cannot be traced to Indo-European or other regional languages, including names like Achilles, Odysseus, and Athens, as well as common words like labyrinth and olive. Linguists believe these words were borrowed from Paleo-European languages spoken by Early European Farmers who preceded Indo-European peoples in the Mediterranean region. As Greek speakers encountered unfamiliar flora, fauna, and geography, they adopted local terminology rather than inventing new words.