Edges of mousseline sleeves regularly fray (5)
I believe the answer is:
melee
'fray' is the definition.
(I've seen this in another clue)
'edges of mousseline sleeves regularly' is the wordplay.
'edges of' suggests removing the centre.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'mousseline' with its middle removed is 'me'.
The alternating letters of 'sleeves' are 'lee'.
'me'+'lee'='MELEE'
(Other definitions for melee that I've seen before include "Confused crowd" , "Confused fight or scuffle" , "Skirmish" , "Fracas" , "Rumpus" .)