The most common and most likely answer to this crossword clue is the 11 letter word ANAESTHETIC
I've seen this crossword clue in Financial Times
A
N
A
E
S
T
H
E
T
I
C
More clues leading to the result ANAESTHETIC
- Article on tasteful number?
- Number employed in the theatre
- Can hesitate to produce a number
- Number of article relating to a sense of beauty
- Number in china tea set, cracked?
- I can see that could be something that’ll put you out
- Number act in haste, upset about drug
- An attractive number
- Number Ten ace has it refurbished
- ‘Number Ten’ ace has it worked out
Buddy explains!

The straight part
We know that "a number" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a number = anaesthetic.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 ANAESTHETIC mean?
ANAESTHETIC noun- A substance administered to reduce the perception of pain or to induce numbness for surgery and may render the recipient unconscious.
- Causing anesthesia; reducing pain sensitivity.
- Insensate: unable to feel, or unconscious.