General, in Venice, to return greeting (7)
I believe the answer is:
othello
'general in venice' is the definition.
'othello' can be an answer for 'general' (I've seen this before). I am not sure about the 'in venice' bit.
'to return greeting' is the wordplay.
'return' says the letters should be written in reverse.
'greeting' becomes 'hello' (hello is a kind of greeting).
'to' backwards is 'ot'.
'ot'+'hello'='OTHELLO'
Can you help me to learn more?
(Other definitions for othello that I've seen before include "Dramatic work" , "Shakespeare play set in Venice/Cyprus" , "player from Stratford" , "Dramatic Moor" , "drama!" .)