Folds in garments held by stitching (6)
I believe the answer is:
pleats
'folds in garments held by stitching' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pleats that I've seen before include "As before, twists" , "Double folds in garments" , "Folds sewn or pressed into cloth" , "Staple for cloth folds" , "Creases, folds" .)