Fruit began going bad in truck (10)
I believe the answer is:
loganberry
'fruit' is the definition.
(loganberry is a kind of fruit)
'began going bad in truck' is the wordplay.
'going bad' is an anagram indicator.
'in' is an insertion indicator.
'truck' becomes 'lorry' (lorry is a kind of truck).
'began' is an anagram of 'ganbe'.
'ganbe' inserted into 'lorry' is 'LOGANBERRY'.
(Other definitions for loganberry that I've seen before include "Hybrid fruit plant" , "Edible soft red fruit" .)