It's true I will appear in the screen version (7)
I believe the answer is:
sincere
'it's true' is the definition.
(similar in meaning)
'i will appear in the screen version' is the wordplay.
'will appear in' is an insertion indicator.
'version' indicates an anagram.
'screen' anagrammed gives 'sncere'.
'i' put inside 'sncere' is 'SINCERE'.
(Other definitions for sincere that I've seen before include "Candid" , "(Of person) genuine" , "Showing genuine feelings" , "natural?" , "Perfect" .)