Organised assembly is magnificent (9)

I believe the answer is:

grandiose

'is magnificent' is the definition.
(thesaurus)

'organised assembly' is the wordplay.
'assembly' indicates anagramming the letters.
'organised' is an anagram of 'GRANDIOSE'.

(Other definitions for grandiose that I've seen before include "Ambitious" , "Pretentiously magnificent" , "Impressive, magnificent" , "Planned on a magnificent scale" , "Pretentiously imposing -- organised (anag)" .)

I've seen this clue in The Daily Express.

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