Very special carcass not decomposing (10)

I believe the answer is:

sacrosanct

I'm a little stuck... Click here to teach me more about this clue!

'very special' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?

'carcass not decomposing' is the wordplay.
'carcass not' anagrams to 'SACROSANCT'.
But, I am unsure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for sacrosanct that I've seen before include "Too important to touch" , "above criticism" , "Unchallengeable" , "Too valuable to be changed" , "protected" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.