Bright rising copper's temporarily given housing (6)
I believe the answer is:
lucent
'bright' is the definition.
('lucent' can be similar in meaning to 'bright')
'rising copper's temporarily given housing' is the wordplay.
'rising' shows that the letters should be reversed in order (going up in a down clue).
'copper' becomes 'cu' (chemical symbol).
'temporarily given' becomes 'lent'.
'housing' is an insertion indicator.
'cu' in reverse letter order is 'uc'.
'uc' inserted into 'lent' is 'LUCENT'.
(Other definitions for lucent that I've seen before include "'Lambent, luminous (6)'" , "Softly bright or radiant" , "Shining" , "Brilliant" .)