Sells one stocked by roofer given a lift (7)
I believe the answer is:
retails
'sells' is the definition.
(retailing is a kind of selling)
'one stocked by roofer given a lift' is the wordplay.
'one' becomes 'I' (Roman numeral).
'stocked by' indicates putting letters inside.
'roofer' becomes 'slater' (someone who slates a roof).
'given a lift' says the letters should be written backwards.
'i' put into 'slater' is 'sliater'.
'sliater' written backwards gives 'RETAILS'.
(Other definitions for retails that I've seen before include "Sells" , "Peddles" .)