Monarchs (father and child) embody uniform pomp (8)
I believe the answer is:
grandeur
'pomp' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
(Other definitions for grandeur that I've seen before include "Nobility, dignity" , "Majesty - eminence" , "Splendour, impressiveness" , "Impressiveness of appearance" , "Majesty (God's, Hopkins)" .)