The most common and most likely answer to this crossword clue is the 9 letter word OPERATING
I've seen this crossword clue in The Daily Telegraph
O
P
E
R
A
T
I
N
G
More clues leading to the result OPERATING
- Oscar training, sailor running
- Opportunity strikebreaker provided for knight working in theatre
- Choosing to save time working
- Spouting off about exercises working
- What’s surgeon doing lecturing about exercises?
- What surgeon might be doing — lecturing about physical exercise
- Running ordinary exercise class
- Controlling Aida, perhaps, with the sound of a bell
- Music drama can go endlessly on
- An ego trip surprisingly producing an effect
Buddy explains!

The straight part
We know that "What’s surgeon doing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what’s surgeon doing = operating.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 OPERATING mean?
OPERATING verb- To perform a work or labour; to exert power or strength, physical or mechanical; to act.
- To produce an appropriate physical effect; to issue in the result designed by nature; especially to take appropriate effect on the human system.
- To act or produce effect on the mind; to exert moral power or influence.
- To perform some manual act upon a human body in a methodical manner, and usually with instruments, with a view to restore soundness or health, as in amputation, lithotomy, etc.
- To deal in stocks or any commodity with a view to speculative profits.
- To produce, as an effect; to cause.
- To put into, or to continue in, operation or activity; to work.
- In operation; that operates.
- Involved in an operation.