Cart reversed three feet (4)
I believe the answer is:
dray
'cart' is the definition.
(a cart without sides for delivering heavy loads)
'reversed three feet' is the wordplay.
'reversed' says the letters should be written backwards.
'three feet' becomes 'yard' (I've seen this before).
'yard' in reverse letter order is 'DRAY'.
(Other definitions for dray that I've seen before include "Draught horse" , "Delivery cart" , "Brewery wagon" , "Flat-bed truck" , "Heavy load-carrying vehicle" .)