Coils of yarn (6)
I believe the answer is:
skeins
'coils of yarn' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for skeins that I've seen before include "Hanks of yarn" , "Coils of yarn" , "Lengths of yarn, loosely coiled" , "Loosely coiled bundles of wood" , "Flocks of geese" .)