Avocado's center (3)
I believe the answer is:
pit
'avocado's center' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pit that I've seen before include "part of theatre" , "Where the orchestra sits to accompany performers" , "Cherry-stone" , "Place for the accompanying orchestra" , "Quarry" .)