Ready to eat? Tear back from office (4)
I believe the answer is:
ripe
'ready to eat?' is the definition.
(I've seen this before)
'tear back from office' is the wordplay.
'tear' becomes 'rip' (synonyms).
'back from' suggests the final letters (the letter at the back of the word).
The last letter of 'office' is 'e'.
'rip'+'e'='RIPE'
(Other definitions for ripe that I've seen before include "Mature, ready for eating" , "Mellow" , "Strong-smelling" , "Mature, ready for harvesting" , "Ready for harvesting, in its prime" .)