The most common and most likely answer to this crossword clue is the 8 letter word PRIGGISH
I've seen this crossword clue in The Daily Telegraph
P
R
I
G
G
I
S
H
More clues leading to the result PRIGGISH
- Sanctimonious expression of contempt about Diana?
- Greedy bears run like 20
- Sanctimonious, having a tendency to scoff about Right
- Smug: as a swine entertaining king
- Sanctimonious and greedy, swallowing last of eclair
- Nonsense about actress Diana being smug
- ‘Obnoxious’ about right for ‘smug’
- Proper greedy, eating last bit of supper
- Puritanical nonsense written about English actress
- Sanctimonious and greedy lapping up last drop of sambar
Buddy explains!

The straight part
We know that "Sanctimonious" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sanctimonious = priggish.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 PRIGGISH mean?
PRIGGISH adjective- Like a prig.