I sell broken thread (5)
I believe the answer is:
lisle
'thread' is the definition.
(I know that lisle is a type of cotton)
'i sell broken' is the wordplay.
'broken' indicates anagramming the letters.
'i'+'sell'='isell'
'isell' anagrammed gives 'LISLE'.
(Other definitions for lisle that I've seen before include "Pedestrianised city" , "Strong twisted cotton thread for the strange Ellis" , "Maker of hose" , "Strong cotton material" , "Cotton stocking thread" .)