Thessalian

Deceitful, fraudulent; hence Θεσσαλων νoμισμα = fraud or deceit. Θεσσαλων σoφισμα = double dealing, referring to the double-dealing of the Thessalians with their confederates, a notable instance of which occurred in the Peloponnesian War where, in the very midst of the battle, they turned sides, deserting the Athenians and going over to the Lacedæmonians. The Locrians had a similar bad repute, whence Λoκρων συνθημα; but of all people, the Spartans were most noted for treachery.