Large insect going in French bread fruit (8)
I believe the answer is:
plantain
'fruit' is the definition.
(I've seen this before)
'large insect going in french bread' is the wordplay.
'large' becomes 'l'.
'insect' becomes 'ant' (ant is a kind of insect).
'going in' is an insertion indicator.
'french bread' becomes 'pain' (I've seen this before).
'l'+'ant'='lant'
'lant' placed within 'pain' is 'PLANTAIN'.
(Other definitions for plantain that I've seen before include "Large banana - weed" , "Pal at inn (anag)" , "Banana-like fruit" , "Cooking banana" , "Low-growing plant; type of banana" .)