Figure involved in Media Monday (7)
I believe the answer is:
diamond
'figure' is the definition.
(thesaurus)
'involved in media monday' is the wordplay.
'involved in' says the answer is hidden in the clue.
'DIAMOND' is hidden within 'media monday'.
(Other definitions for diamond that I've seen before include "nickname of US State" , "Hard precious stone" , "Form of carbon" , "A suit; a gem" , "Stone - card" .)