Very large piece of meat saved to take back (4)
I believe the answer is:
vast
'very large' is the definition.
(I know this)
'piece of meat saved to take back' is the wordplay.
'piece of' says the answer is hidden in the clue.
'to take back' says the letters should be written backwards (I've seen 'taken back' mean this).
'tsav' is hidden in the letters of 'meat saved'.
'tsav' back-to-front is 'VAST'.
(Other definitions for vast that I've seen before include "Colossal" , "Unusually great" , "Huge, enormous" , "Extremely large or extensive" , "'Huge, immense (4)'" .)