Unit of weight of silk and nylon (6)
I believe the answer is:
denier
'unit of weight of silk and nylon' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for denier that I've seen before include "Unit of measurement for silk" , "measure of yarn's quality" , "Conspiracist probably" , "Peter?" , "One refusing to accept" .)