The Fool — as shown in the cards? (7)
I believe the answer is:
jackass
'the fool' is the definition.
(jackass is a kind of fool)
'as shown in the cards?' is the wordplay.
'shown in' indicates putting letters inside.
'the cards?' becomes 'jacks' (jack is a kind of card).
'as' placed within 'jacks' is 'JACKASS'.
(Other definitions for jackass that I've seen before include "See 7" , "Male donkey - fool" , "Male donkey; idiot" , "One may lark about" , "Blockhead" .)