Soldier emptied lorry at uniform intervals (9)
I believe the answer is:
regularly
'at uniform intervals' is the definition.
I can't tell whether this definition defines the answer.
'soldier emptied lorry' is the wordplay.
'soldier' becomes 'regular' (member of the regular army).
'emptied' suggests removing the centre.
'lorry' with its centre taken out is 'ly'.
'regular'+'ly'='REGULARLY'
Can you help me to learn more?
(Other definitions for regularly that I've seen before include "at the same time" , "At fixed intervals" , "Often - at intervals" , "Evenly" , "How shoes will appear in schooners" .)