Attendant and soldier supported by ridiculously empty pomp (9)
I believe the answer is:
pageantry
'pomp' is the definition.
(thesaurus)
'attendant and soldier supported by ridiculously empty' is the wordplay.
'attendant' becomes 'page' (page is a kind of attendant).
'and' is a charade indicator (letters next to each other).
'soldier' becomes 'ant' (I've seen this before).
'supported by' means one lot of letters go next to another (letters go below - in down clue).
'ridiculously empty' becomes 'ry' (I can't explain this - if you can you should give a lot more credence to this answer).
'page'+'ant'+'ry'='PAGEANTRY'
Can you help me to learn more?
(Other definitions for pageantry that I've seen before include "Spectacle" , "Show" , "Splendid display" .)