Stunned when lorry gets both of us on board (9)
I believe the answer is:
awe-struck
'stunned' is the definition.
(I've seen this before)
'when lorry gets both of us on board' is the subsidiary indication.
'when' becomes 'as'.
'lorry' becomes 'truck' (I've seen this before).
'gets' means one lot of letters go next to another.
'both of us' becomes 'we'.
'on board' indicates putting letters inside.
'as'+'truck'='astruck'
'astruck' placed around 'we' is 'awestruck'.
(Other definitions for awe-struck that I've seen before include "Stunned" , "Suck water (anag) - completely astonished" , "Dumbfounded" , "Filled with amazement" , "Most impressed" .)