Fanciful lie marked as unreal (9)
I believe the answer is:
dreamlike
'unreal' is the definition.
(similar in meaning)
'fanciful lie marked' is the wordplay.
'fanciful' indicates anagramming the letters (a fanciful or silly ordering of the letters).
'lie'+'marked'='liemarked'
'liemarked' is an anagram of 'DREAMLIKE'.
'as' is the link.
(Other definitions for dreamlike that I've seen before include "Imagined" , "Illusory" .)