Iron Lady displays top fashion (6)
I believe the answer is:
fedora
'top fashion' is the definition.
(I've seen this before)
'iron lady' is the wordplay.
'iron' becomes 'Fe' (Fe is the chemical symbol for iron).
'lady' becomes 'dora' ().
'fe'+'dora'='FEDORA'
'displays' acts as a link.
(Other definitions for fedora that I've seen before include "Soft felt hat with a curled brim" , "Type of hat" , "Headwear" , "Felt hat, dented lengthwise" , "Or fade away with man's soft felt hat" .)