Noted Conservative bet leader changes (10)
I believe the answer is:
celebrated
'noted' is the definition.
('celebrated' can be a synonym of 'noted')
'conservative bet leader changes' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'changes' indicates an anagram.
'bet'+'leader'='betleader'
'betleader' with letters rearranged gives 'elebrated'.
'c'+'elebrated'='CELEBRATED'
(Other definitions for celebrated that I've seen before include "Rejoiced - famous" , "Publicly honoured" , "Cheered" , "Notable" , "Did something enjoyable (to mark an event)" .)