I agree - Government bond or loan.
Greece in this era was in its second republic (1922 - 1935), after they had deposed the king and it was unstable. Inflation was worsening, so it would have been worth a lot less purchasing wise in 1934 than in 1926 when it was issued, the numbers suggest 5 units in whatever trust or bond it was.
The top word says “Treasury of Greece” - which is found on most of their banknotes.
I love coins. Especially silver, gold and anything really old.
Member of the Royal Numismatic Society of New Zealand and the Auckland Numismatic Society