Such pomp may cover a joke (7)
I believe the answer is:
majesty
'such pomp' is the definition.
'majesty' can be an answer for 'pomp' (I've seen this in another clue). I'm not sure about the 'such' bit.
'may cover a joke' is the wordplay.
'cover' indicates putting letters inside.
'a joke' becomes 'jest' ('jest' can be a synonym of 'joke').
'may' going around 'jest' is 'MAJESTY'.
Can you help me to learn more?
(Other definitions for majesty that I've seen before include "Royal quality" , "Regal dignity" , "title" , "Grandeur" , "Supreme power" .)