Frightens about five in mufflers (7)
I believe the answer is:
scarves
'mufflers' is the definition.
(I've seen this in another clue)
'frightens about five' is the wordplay.
'frightens' becomes 'scares' ('scare' can be a synonym of 'frighten').
'about' indicates putting letters inside.
'five' becomes 'V' (Roman numeral).
'scares' going around 'v' is 'SCARVES'.
'in' is the link.
(Other definitions for scarves that I've seen before include "Neck or head garments" , "Headsquares" , "headwear" , "Winter warmers" .)