Crazy Lear isn't showing what's inside (8)
I believe the answer is:
entrails
'what's inside' is the definition.
(thesaurus)
'crazy lear isn't' is the wordplay.
'crazy' indicates anagramming the letters.
'lear'+'isnt'='learisnt'
'learisnt' is an anagram of 'ENTRAILS'.
'showing' acts as a link.
(Other definitions for entrails that I've seen before include "Intestines of animals" , "Bowels or intestines" , "Intestines, guts" , "Internal organs of animals" , "Intestines found in latrines" .)