The most common and most likely answer to this crossword clue is the 9 letter word HEAVINESS
I've seen this crossword clue in The Daily Telegraph
H
E
A
V
I
N
E
S
S
More clues leading to the result HEAVINESS
Buddy explains!
The straight part
We know that "Pomposity" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pomposity = heaviness.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HEAVINESS mean?
HEAVINESS noun- The state of being heavy; weight, weightiness, force of impact or gravity.
- Oppression; dejectedness, sadness; low spirits.
- Drowsiness.