The most common and most likely answer to this crossword clue is the 9 letter word PHONETICS
I've seen this crossword clue in The Daily Telegraph
P
H
O
N
E
T
I
C
S
More clues leading to the result PHONETICS
Buddy explains!
The straight part
We know that "in this discipline?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in this discipline? = phonetics.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 PHONETICS mean?
PHONETICS noun- The study of the physical sounds of human speech, concerned with the physical properties of speech sounds (phones), and the processes of their physiological production, auditory reception, and neurophysiological perception, and their representation by written symbols.