Knitter's ball (4)
I believe the answer is:
yarn
'knitter's ball' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yarn that I've seen before include "Story, and thread or wool, say" , "Long involved story" , "Spun thread; long story" , "Spun fibre" , "Spun thread or wool or tall tale" .)