Canniest new case in point (8)
I believe the answer is:
instance
'case in point' is the definition.
(I've seen this before)
'canniest new' is the wordplay.
'new' indicates anagramming the letters.
'canniest' with letters rearranged gives 'INSTANCE'.
(Other definitions for instance that I've seen before include "A case or example of something" , "'Example, illustration (8)'" , "Particular case; cite" , "Cite as an example" , "Particular example" .)