Critique regarding appearance (6)
I believe the answer is:
review
'critique' is the definition.
(I know that critique can be written as review)
'regarding appearance' is the wordplay.
'regarding' becomes 're' ('re' means regarding or about).
'appearance' becomes 'view' (view is a kind of appearance).
're'+'view'='REVIEW'
(Other definitions for review that I've seen before include "Critic's article" , "notice" , "'Critique, appraisal (6)'" , "Critique by viewer" , "Formal assessment" .)