Vegetable lorry OK, the man accepts (9)
I believe the answer is:
artichoke
'vegetable' is the definition.
(artichoke is a kind of vegetable)
'lorry ok the man accepts' is the wordplay.
'lorry' becomes 'artic' (articulated lorry is a semi-trailer truck).
'the man' becomes 'he'.
'accepts' is an insertion indicator.
'ok' inserted into 'he' is 'hoke'.
'artic'+'hoke'='ARTICHOKE'
(Other definitions for artichoke that I've seen before include "Thistlelike edible flower head" , "Vegetable could give you a thicko ear" , "globe, for example" , "Thistle-like plant with edible heads" , "Plant with large edible flower-head" .)