Tall story with article about extraterrestrial (5)
I believe the answer is:
alien
'extraterrestrial' is the definition.
('alien' can be a synonym of 'extraterrestrial')
'tall story with article about' is the wordplay.
'tall story' becomes 'neil' (I can't explain this - if you can you should give a lot more credence to this answer).
'with' is a charade indicator (letters next to each other).
'article' becomes 'a' (indefinite article).
'about' is a reversal indicator.
'neil'+'a'='neila'
'neila' reversed gives 'ALIEN'.
Can you help me to learn more?
(Other definitions for alien that I've seen before include "Being from another world" , "Foreigner, outsider" , "coming from overseas" , "exciting film based in space" , "Foreign, strange" .)