Blur faces but nothing otherwise (9)
I believe the answer is:
obfuscate
'blur' is the definition.
(both can mean to make more confusing)
'faces but nothing otherwise' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'otherwise' indicates anagramming the letters.
'faces'+'but'+'o'='facesbuto'
'facesbuto' anagrammed gives 'OBFUSCATE'.
(Other definitions for obfuscate that I've seen before include "Darken or obscure something" , "Make unintelligible" , "Make confused" , "Hide" , "Perplex" .)