Is mad about a king with a golden touch (5)
I believe the answer is:
midas
'a king with a golden touch' is the definition.
(I've seen this in another clue)
'is mad about' is the wordplay.
'about' indicates an anagram.
'is'+'mad'='ismad'
'ismad' is an anagram of 'MIDAS'.
(Other definitions for midas that I've seen before include "Mythical king who had the power to turn everything to gold" , "my gift turned out a curse" , "King of Phrygia who had a golden touch" , "Legendary king with golden touch" , "Gold-creating king" .)