The mess around the border (3)
I believe the answer is:
hem
'the border' is the definition.
(I've seen this before)
'the mess around' is the wordplay.
'around' says the answer is hidden in the clue.
'HEM' is hidden in the letters of 'the mess'.
(Other definitions for hem that I've seen before include "Part of skirt" , "Double-backed cloth border" , "Express hesitation" , "Sewn border" , "Finished edge of a piece of cloth" .)