Confusion when letter from Greece gets delivered late with contents missing (6)
I believe the answer is:
muddle
'confusion' is the definition.
(I've seen this in another clue)
'letter from greece gets delivered late with contents missing' is the wordplay.
'letter from greece' becomes 'mu' (letter from the Greek alphabet).
'gets' is a charade indicator (letters next to each other).
'delivered' becomes 'dd' (I can't justify this - if you can you should believe this answer much more).
'with contents missing' says to hollow out the word (remove centre letters).
'late' with its centre removed is 'le'.
'mu'+'dd'+'le'='MUDDLE'
'when' acts as a link.
(Other definitions for muddle that I've seen before include "Confused state" , "[OPPOSITE OF] clear" , "disorderly state of affairs" , "Confusion - mess" , "Clutter" .)