Took a meal back for Greek character (3)
I believe the answer is:
eta
'greek character' is the definition.
(letter from the Greek alphabet)
'took a meal back' is the wordplay.
'took a meal' becomes 'ate' (to eat is to have a meal).
'back' says the letters should be written in reverse.
'ate' reversed gives 'ETA'.
'for' is the link.
(Other definitions for eta that I've seen before include "when it might reach us?" , "Letter from Doris" , "Letter from abroad" , "Basque separatist movement" , "indicating when flight is due" .)