Small cart backing several feet (5)
I believe the answer is:
yards
'several feet' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe you can see a link between them that I can't see?
'small cart backing' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'cart' becomes 'dray' (a cart without sides for delivering heavy loads).
'backing' says the letters should be written backwards.
's'+'dray'='sdray'
'sdray' reversed gives 'YARDS'.
Can you help me to learn more?
(Other definitions for yards that I've seen before include "Farm enclosures?" , "Measures; enclosures" , "Three feet in each" , "Pieces of uncultivated ground adjoining buildings" , "Units of length" .)