On the surface, skin-deep (11)
I believe the answer is:
superficial
This clue is a double definition.
'on the surface' is the first definition.
(thesaurus)
'skin-deep' is the second definition.
(similar in meaning)
(Other definitions for superficial that I've seen before include "12 [TWO DIMENSIONAL]" , "Cursory" , "Not profound" , "Far from thorough" .)