Yarn coil (5)
I believe the answer is:
skein
'yarn coil' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for skein that I've seen before include "Hank" , "Clock face" , "Loosely-coiled bundle of wool" , "Loosely coiled length of thread" , "Flock of flying geese" .)