Carve letters in Greek and English one spelled out (6)
I believe the answer is:
chisel
'carve' is the definition.
(chiseling is a kind of carving)
'letters in greek and english one spelled out' is the wordplay.
'letters in greek' becomes 'chis' (chi is a Greek letter).
'and' says to put letters next to each other.
'english' becomes 'e' (abbreviation).
'one spelled out' becomes 'l' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'chis'+'e'+'l'='CHISEL'
(Other definitions for chisel that I've seen before include "Slangily cheat with wood-working tool" , "Hand tool to shape wood" , "Tool used to shape wood, stone or metal" , "Sharp-edged metal tool" , "Sharp tool" .)