Like The Onion , CIA trials collapsed (9)
I believe the answer is:
satirical
'like the onion' is the definition.
(I've seen this in another clue)
'cia trials collapsed' is the wordplay.
'collapsed' indicates anagramming the letters.
'cia'+'trials'='ciatrials'
'ciatrials' with letters rearranged gives 'SATIRICAL'.
(Other definitions for satirical that I've seen before include "Ridiculing" , "Ironic - sarcastic" , "scornful" , "Humorously critical" , "Mocking" .)