Fashion line displayed in eyesore (5)
I believe the answer is:
style
'fashion' is the definition.
('style' can be a synonym of 'fashion')
'line displayed in eyesore' is the wordplay.
'line' becomes 'l'.
'displayed in' indicates putting letters inside.
'eyesore' becomes 'stye' (I've seen this before).
'l' inserted within 'stye' is 'STYLE'.
(Other definitions for style that I've seen before include "Fashion or design" , "Cut dash" , "Official title; manner" , "Showy way of life - elegance" , "Fashion or way of doing things" .)