Strand of cotton (6)
I believe the answer is:
thread
'strand of cotton' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for thread that I've seen before include "Line of cotton - plot (of book, film)" , "Dearth of stitching material" , "Hatred (anag)" , "Cord - Internet chat room discussion" , "Dearth of sewing material" .)