Superficially attractive (12)
I believe the answer is:
meretricious
'superficially attractive' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for meretricious that I've seen before include "Superficially attractive but worthless" , "Showy" , "Courier-Times (anag) - tacky" , "showily attractive" , "Flashy" .)