The most common and most likely answer to this crossword clue is the 9 letter word UPSETTING
I've seen this crossword clue in The Daily Telegraph
U
P
S
E
T
T
I
N
G
More clues leading to the result UPSETTING
- Disturbing, being out of bed doing my job?
- Disturbing, being out of bed and doing my job!
- Distressing way to increase crossword output?
- Tipping over pint, guest must be smashed
- Happy environment or sad?
- Excited to be creating puzzles, if traumatic
- After receiving promotion, going down is distressing
- Alarming seeing one in gents put out
- Out of bed, scenery becomes disturbing
- What I am doing now after getting high is worrying
Buddy explains!

The straight part
We know that "disturbing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case disturbing = upsetting.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 UPSETTING mean?
UPSETTING verb- To make (a person) angry, distressed, or unhappy.
- To disturb, disrupt or adversely alter (something).
- To tip or overturn (something).
- To defeat unexpectedly.
- To be upset or knocked over.
- To set up; to put upright.
- To thicken and shorten, as a heated piece of iron, by hammering on the end.
- To shorten (a tire) in the process of resetting, originally by cutting it and hammering on the ends.
- The action of the verb upset.
- Causing upset; distressing.
- Conceited; presumptuous.