Breach by six switching sides in speech (9)
I believe the answer is:
violation
'breach' is the definition.
(I've seen this before)
'by six switching sides in speech' is the wordplay.
I cannot really see how this works, but
'by' could be 'at' and 'at' is present in the answer.
'six' could be 'vi' (roman numeral) and 'vi' is found in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for violation that I've seen before include "outrage" , "abuse" , "Infringement" , "Offence" , "Breach" .)