Gaudy rig has to be replaced (6)
I believe the answer is:
garish
'gaudy' is the definition.
('garish' can be a synonym of 'gaudy')
'rig has to be replaced' is the wordplay.
'to be replaced' indicates an anagram.
'rig'+'has'='righas'
'righas' anagrammed gives 'GARISH'.
(Other definitions for garish that I've seen before include "Gaudy, vulgarly bright" , "Gaudy, over-decorated" , "Obtrusively bright" , "Gaudy, showy" , "Cheap, flash" .)