The most common and most likely answer to this crossword clue is the 9 letter word MASTICATE
I've seen this crossword clue in The Guardian
M
A
S
T
I
C
A
T
E
More clues leading to the result MASTICATE
- Spouse quaffs wine, about to deal with mouthful
- Make use of Jaws with international cast at sea in China
- Chew gum, having drunk tea
- Assistant keeps wine cold for champ
- Is cat meat made to chew?
- Team acts badly protecting single champ
- ‘Best friend’ catching a cut branch to chew
- Champ married bubbly Blanchett
- Act as time runs out for champ
- Champ Ramki, essentially aces at setting with it
Buddy explains!

The straight part
We know that "crunch" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case crunch = masticate.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 MASTICATE mean?
MASTICATE verb- To chew (food).
- To grind or knead something into a pulp.