Travelled back after seeing opening of Fred Astaire's Top Hat (6)
I believe the answer is:
fedora
'hat' is the definition.
(I know that fedora is a type of hat)
'travelled back after seeing opening of fred astaire's top' is the wordplay.
'travelled' becomes 'rode' (I've seen this before).
'back' is a reversal indicator.
'after' means one lot of letters go next to another.
'seeing opening of' indicates taking the first letters.
'top' says to take the initial letters.
The first letter of 'fred' is 'f'.
The first letter of 'astaires' is 'a'.
'rode' backwards is 'edor'.
'edor' after 'f' is 'fedor'.
'fedor'+'a'='FEDORA'
(Other definitions for fedora that I've seen before include "Felt hat dented lengthways" , "Felt hat with a creased crown" , "O, Fred, a hat becomes you" , "Headgear" , "Cover for head" .)