Organised in pompous fashion (9)
I believe the answer is:
grandiose
'organised in pompous fashion' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives sometimes define each other.
'organised in pompous fashion' is the wordplay.
'organised' anagrams to 'GRANDIOSE'.
Though, I am unsure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for grandiose that I've seen before include "Impressive in style" , "Ridiculously impressive or imposing" , "affected" , "Pretentiously impressive" , "Pretentiously imposing -- organised (anag)" .)