ξυλοκέφαλος

From LSJ

τὸν ἀφ' ἱερᾶς κινεῖν λίθον → move one's man from this line, move a piece from this line, try one's last chance, make a last ditch effort

Source

Greek Monolingual

-η, -ο
(υβριστικά) αυτός που δεν μαθαίνει εύκολα, ηλίθιος, ξεροκέφαλος.