Attend a corps feast, then leave hurriedly (4,1,7)
I believe the answer is:
beat a retreat
'attend' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how one could define the other.
'a corps feast then leave hurriedly' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
'corps' could be 're' (Royal Engineers army regiment) and 're' is present in the answer.
'feast' could be 'eat' (I've seen this in another clue) and 'eat' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for beat a retreat that I've seen before include "Depart hastily" , "Withdraw quickly" , "Retire hastily" , "Withdraw to avoid something unpleasant" , "Go away in a hurry" .)