The most common and most likely answer to this crossword clue is the 10 letter word SHATTERING
I've seen this crossword clue in The Sunday Telegraph
S
H
A
T
T
E
R
I
N
G
More clues leading to the result SHATTERING
- Very shocking squeal enveloping milliner
- Terrible threat lying within grass could be overwhelming
- Working nights, rate terrible
- Very upsetting, gun wings a girth badly
- Disturbed night? A rest would be smashing!
- Smashing fellow deemed mad is lying in grass
- Terrible milliner: give voice about that
- Carelessly straighten, breaking to small shards
- 21a
Buddy explains!
The straight part
We know that "Terrible" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case terrible = shattering.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 SHATTERING mean?
SHATTERING verb- To violently break something into pieces.
- To destroy or disable something.
- To smash, or break into tiny pieces.
- To dispirit or emotionally defeat
- To scatter about.
- The act of something that shatters; the shattered material