Tacit reform for Upper House? (5)
I believe the answer is:
attic
'upper house?' is the definition.
(I've seen this in another clue)
'tacit reform' is the wordplay.
'reform' is an anagram indicator (letters in a new form).
'tacit' anagrammed gives 'ATTIC'.
'for' acts as a link.
(Other definitions for attic that I've seen before include "Ancient Greek dialect - top room" , "Top level" , "Greek - garret" , "Upper chamber" , "Top apartment" .)