Measure used by drapers and jewellers (3)
I believe the answer is:
ell
'measure' is the definition.
(historical unit of length)
'by drapers and jewellers' is the wordplay.
'ELL' is hidden within the letters.
However, I am uncertain how this is indicated.
'used' acts as a link.
Can you help me to learn more?
(Other definitions for ell that I've seen before include "45 inches (cloth)" , "Measure, approx. fourty-five in." , "Length of cloth" , "railway in Chicago?" , "Old measure equivalent to about 45 inches in England" .)