Utterly pompous (7)
I believe the answer is:
orotund
'pompous' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for orotund that I've seen before include "Full, round" , "Pompous (oratory)" , "Bombastic" , "Pompous (in style)" , "Full in sound" .)