Committee added to trophy cabinet (8)
I believe the answer is:
cupboard
'cabinet' is the definition.
(I've seen this before)
'committee added to trophy' is the wordplay.
'committee' becomes 'board' (board is a kind of committee).
'added to' means one lot of letters go next to another.
'trophy' becomes 'cup' (cup is a kind of trophy).
'board' put after 'cup' is 'CUPBOARD'.
(Other definitions for cupboard that I've seen before include "Store for crockery etc" , "Storage cabinet" , "Piece of furniture in which things are stored" , "Hubbard found it bare" , "Storage place" .)