Fruit left worker in agony (8)
I believe the answer is:
plantain
'fruit' is the definition.
(thesaurus)
'left worker in agony' is the wordplay.
'left' becomes 'l' (common abbreviation).
'worker' becomes 'ant' (worker is a type of ant).
'in' is an insertion indicator.
'agony' becomes 'pain' (I've seen this before).
'l'+'ant'='lant'
'lant' placed into 'pain' is 'PLANTAIN'.
(Other definitions for plantain that I've seen before include "Tropical plant like a banana" , "Sort of banana" , "Tropical food" , "Cooking banana" , "Banana-like fruit" .)