Cart pulled back miles by an outdoor labourer (7)
I believe the answer is:
yardman
'outdoor labourer' is the definition.
The definition suggests a singular noun which matches the answer.
'cart pulled back miles by an' is the wordplay.
'cart' becomes 'dray' (a cart without sides for delivering heavy loads).
'pulled back' shows that the letters should be reversed in order.
'miles' becomes 'm' (common abbreviation).
'by' says to put letters next to each other.
'dray' backwards is 'yard'.
'yard'+'m'+'an'='YARDMAN'
Can you help me to learn more?
(Another definition for yardman that I've seen is " Farm worker".)