Taiwan's top philosopher accumulated household items for union (9)
I believe the answer is:
trousseau
'accumulated household items for union' is the definition.
'taiwan's top philosopher' is the wordplay.
'taiwan's top' becomes 't' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'philosopher' becomes 'rousseau' (Rousseau is an example).
't'+'rousseau'='TROUSSEAU'
(Other definitions for trousseau that I've seen before include "Clothes collected for a purpose" , "All that a bride needs!" , "Bride's clothes and linen collection" , "One's prepared for wedding" , "wedding gear" .)