Deceptive (8)
I believe the answer is:
illusory
'deceptive' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for illusory that I've seen before include "false" , "Fanciful, imaginary (8)" , "Unreal, fanciful" , "in the imagination" , "Not real, imagined" .)