Initially terrified, Warhol is being treated for poor hearing (4,5)
'poor hearing' is the definition.
(legal hearing with predetermined outcome)
'initially terrified warhol is being treated' is the wordplay.
'initially' says to take the initial letters.
'being treated' indicates an anagram.
The initial letter of 'terrified' is 't'.
'twarholis' with letters rearranged gives 'SHOW TRIAL'.
'for' is the link.
(Other definitions for show trial that I've seen before include "This process manipulated", "legal spectacular", "Court proceedings where the guilty decision has been decided in advance", "Mock public examination", "Travesty of justice".)