Harvest fruit? Come again! (8)
I believe the answer is:
reappear
'come again' is the definition.
(thesaurus)
'harvest fruit?' is the wordplay.
'harvest' becomes 'reap' (synonyms).
'fruit?' becomes 'pear' (pear is a kind of fruit).
'reap'+'pear'='REAPPEAR'
(Other definitions for reappear that I've seen before include "crop up again" , "return" , "spring up again?" , "Be seen again" , "Come into view again" .)