Stitch around back of skirt causing worry (4)
I believe the answer is:
stew
'worry' is the definition.
(I've seen this before)
'stitch around back of skirt' is the wordplay.
'stitch' becomes 'sew' ('sew' can be a synonym of 'stitch').
'around' means one lot of letters goes inside another.
'back of' indicates one should take the final letters.
The last letter of 'skirt' is 't'.
'sew' going around 't' is 'STEW'.
'causing' is the link.
(Other definitions for stew that I've seen before include "Swelter" , "Artificial oyster bed" , "overheated condition" , "Cook slowly and for a long time in liquid" , "Slow cooked meat dish" .)