Constant guest at iconic shows (6)
I believe the answer is:
static
'constant' is the definition.
(I've seen this in another clue)
'guest at iconic shows' is the wordplay.
'shows' indicates the answer is hidden within the clue.
'STATIC' is hidden within 'guest at iconic'.
(Other definitions for static that I've seen before include "it can shock and > ruin the reception" , "fixed" , "8-ing - sort of electricity, line or memory" , "Inert, motionless" , "Atmospheric disturbance" .)