Posher canine celebrity wearing collar frills? (8)
I believe the answer is:
classier
'posher' is the definition.
('classy' can be a synonym of 'posh')
'canine celebrity wearing collar frills?' is the wordplay.
'canine celebrity' becomes 'lassie' (I can't justify this - if you can you should give a lot more credence to this answer).
'wearing' is an insertion indicator.
'frills?' says to hollow out the word (remove centre letters) (I've seen 'frills' mean this (frills can mean decorative edges)).
'collar' with its centre taken out is 'cr'.
'lassie' placed inside 'cr' is 'CLASSIER'.
Can you help me to learn more?
(Other definitions for classier that I've seen before include "Tony increasingly" , "superior?" , "More sophisticated or stylish" , "Smarter" .)